US20070034862A1 - Electronic device comprising an organic semiconductor, an organic semiconductor, and an intermediate buffer layer made of a polymer that is cationically polymerizable and contains no photoacid - Google Patents

Electronic device comprising an organic semiconductor, an organic semiconductor, and an intermediate buffer layer made of a polymer that is cationically polymerizable and contains no photoacid Download PDF

Info

Publication number
US20070034862A1
US20070034862A1 US10/570,640 US57064004A US2007034862A1 US 20070034862 A1 US20070034862 A1 US 20070034862A1 US 57064004 A US57064004 A US 57064004A US 2007034862 A1 US2007034862 A1 US 2007034862A1
Authority
US
United States
Prior art keywords
electronic device
organic
buffer layer
atoms
polymer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/570,640
Inventor
Amir Parham
Aurelie Falcou
Susanne Heun
Jurgen Steiger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Merck Patent GmbH
Original Assignee
Covion Organic Semiconductors GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=34258390&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US20070034862(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Covion Organic Semiconductors GmbH filed Critical Covion Organic Semiconductors GmbH
Assigned to MERCK OLED MATERIALS GMBH reassignment MERCK OLED MATERIALS GMBH CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: COVION ORGANIC SEMICONDUCTORS GMBH
Assigned to MERCK PATENT GMBH reassignment MERCK PATENT GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MERCK OLED MATERIALS GMBH
Publication of US20070034862A1 publication Critical patent/US20070034862A1/en
Assigned to COVION ORGANIC SEMICONDUCTORS GMBH reassignment COVION ORGANIC SEMICONDUCTORS GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FALCOU, AURELIE, HEUN, SUSANNE, PARHAM, AMIR, STEIGER, JURGEN, MULLER, DAVID CHRISTOPH, MEERHOLZ, KLAUS
Abandoned legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K10/00Organic devices specially adapted for rectifying, amplifying, oscillating or switching; Organic capacitors or resistors having a potential-jump barrier or a surface barrier
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/20Changing the shape of the active layer in the devices, e.g. patterning
    • H10K71/211Changing the shape of the active layer in the devices, e.g. patterning by selective transformation of an existing layer
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00Organic light-emitting devices
    • H10K50/10OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/17Carrier injection layers
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/10Organic polymers or oligomers
    • H10K85/111Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/10Organic polymers or oligomers
    • H10K85/111Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
    • H10K85/115Polyfluorene; Derivatives thereof
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/10Organic polymers or oligomers
    • H10K85/151Copolymers
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/60Organic compounds having low molecular weight
    • H10K85/631Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2102/00Constructional details relating to the organic devices covered by this subclass
    • H10K2102/10Transparent electrodes, e.g. using graphene
    • H10K2102/101Transparent electrodes, e.g. using graphene comprising transparent conductive oxides [TCO]
    • H10K2102/103Transparent electrodes, e.g. using graphene comprising transparent conductive oxides [TCO] comprising indium oxides, e.g. ITO
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/10Organic polymers or oligomers
    • H10K85/111Organic polymers or oligomers comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
    • H10K85/113Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
    • H10K85/1135Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/50Photovoltaic [PV] energy
    • Y02E10/549Organic PV cells
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/26Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
    • Y10T428/263Coating layer not in excess of 5 mils thick or equivalent
    • Y10T428/264Up to 3 mils
    • Y10T428/2651 mil or less
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/26Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
    • Y10T428/269Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension including synthetic resin or polymer layer or component
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31511Of epoxy ether

Definitions

  • Organic-based charge transport materials generally triarylamine-based hole transporters
  • OLEDs or PLEDs organic or polymeric light emitting diodes
  • O-SCs organic solar cells
  • O-FETs organic field effect transistors
  • O-ICs organic circuit elements
  • O-lasers organic laser diodes
  • organic devices can be produced from solution which entails less technical and cost outlay than vacuum processes, as are generally carried out for low molecular weight compounds.
  • colored electroluminescent devices can be produced comparatively simply by processing the materials by surface coating from solution (for example by spin coating, doctor blade technique, etc.).
  • the structuring, i.e. driving of individual image points, is usually carried out here in the “leads”, i.e. for example in the electrodes. This may, for example, be done using shadow masks in the manner of a template.
  • the structuring of organic circuits and partially organic solar cell panels or laser arrays can be carried out similarly.
  • Shadow masks furthermore cannot be readily employed when, for example, full-color displays or organic circuits with different circuit elements are to be produced.
  • full-color displays the three primary colors (red, green and, blue) in individual pixels (image points) must be applied next to one another with a high resolution. Similar considerations apply to electronic circuits with different circuit elements. While the individual image points can be produced by evaporating the individual colors using shadow masks in the case of low molecular weight evaporatable molecules (with the associated difficulties already mentioned above), this is not possible for polymeric materials and materials processed from solution, and the structuring can no longer be carried out merely by structuring the electrodes.
  • structurable materials are described which are suitable for use in structured devices such as OLEDs, PLEDs, organic lasers, organic circuit elements or organic solar cells. These are organic, in particular electroluminescent materials, which contain at least one oxetane group capable of crosslinking, the crosslinking reaction of which can be deliberately initiated and controlled.
  • electroluminescent materials which contain at least one oxetane group capable of crosslinking, the crosslinking reaction of which can be deliberately initiated and controlled.
  • Macromol. Rapid Commun. 1999, 20, 225 describes N,N,N′,N′-tetraphenylbenzidines functionalized with oxetane groups, which can be crosslinked in a photoinduced way.
  • These compound classes are used as structurable hole conductors directly on the anode of the organic electronic device.
  • At least one photoinitiator is added to the materials for crosslinking.
  • an acid is generated which initiates a crosslinking reaction by cationic ring-opening polymerization.
  • a pattern of regions with crosslinked material and regions with uncrosslinked material can thus be obtained by structured exposure.
  • the regions of uncrosslinked material can then be removed by suitable operations (for example washing with suitable solvents). This leads to the desired structuring.
  • suitable operations for example washing with suitable solvents.
  • Exposure, as employed for the structuring is a standard process in modern electronics and can, for example, be carried out with lasers or by surface exposure using a suitable photomask.
  • the mask does not involve the risk of deposition here, since in this case only radiation and no material flux has to be delimited by the mask.
  • Chem Phys Chem 2000, 207 such a crosslinked triarylamine layer is introduced as an interlayer between a conductive doped polymer and an organic luminescent semiconductor. A higher efficiency is obtained in this case.
  • a photoacid is used for the crosslinking. This appears to be necessary for complete crosslinking of the triarylamine layer.
  • the photoacid or its reaction products remain as contamination in the electronic device after the crosslinking. It is generally acknowledged that both organic and inorganic impurities can perturb the operation of organic electronic devices. For this reason, it would be desirable to be able to reduce the use of photoacids as much as possible.
  • EP 0637899 proposes electroluminescent arrangements having one or more layers in which at least one layer is obtained by thermal or radiation-induced crosslinking, which furthermore contain at least one emitter layer and at least one charge transport unit per layer.
  • the crosslinking may take place radically, ionically, cationically or via a photoinduced ring closure reaction.
  • An advantage mentioned is that a plurality of layers can thereby be formed on one another, or that the layers can also be structured in a radiation-induced way.
  • no teaching is given as to which of the various crosslinking reactions can be used to produce a suitable device, and how the crosslinking reaction can best be carried out.
  • radically crosslinkable units or groups capable of photocycloaddition are preferred, that various types of auxiliaries, for example initiators, may be contained and that the film is preferably crosslinked by means of actinic radiation and not thermally.
  • auxiliaries for example initiators
  • Suitable device configurations are also not described. It is therefore unclear how many layers the device preferably comprises, and how thick they should be, which material classes are preferably used and which of them should be crosslinked. It is therefore also not apparent to the person skilled in the art how the described invention can be successfully implemented in practice.
  • an interlayer of a conductive doped polymer is often introduced as a charge injection layer between the electrode (in particular the anode) and the function material ( Appl. Phys. Lett. 1997, 70, 2067-2069).
  • a conductive doped polymer may also be used directly as the anode (or even as the cathode, depending on the application).
  • the most common of these polymers are polythiophene derivatives (for example poly(ethylenedioxythiophene), PEDOT) and polyaniline (PANI), which are generally doped with polystyrene sulfonic acid or other polymer-bound Brönstedt acids and thus brought into a conductive state.
  • Protons or other cationic impurities have a negative effect in particular when the functional semiconductor layer applied onto this layer is cationically crosslinkable and, as described above, is intended to be structured.
  • the functional layer is already partially or fully crosslinked by the presence of protons or other cationic impurities, without providing the opportunity to control the crosslinking, for example by actinic radiation.
  • the advantage of the controlled structurability is therefore lost.
  • Cationically crosslinkable materials thus in principle do provide the possibility of structuring and therefore an alternative to printing techniques. However, technical implementation of these materials is not to date possible since the problem of uncontrolled crosslinking on a doped charge injection layer is not yet resolved.
  • the electronic properties of the devices can be significantly improved when at least one buffer layer, which is cationically crosslinkable, is introduced between the doped interlayer and the functional organic semiconductor layer.
  • Particularly good properties are obtained with a buffer layer whose cationic crosslinking is induced thermally, i.e. by a temperature rise to from 50 to 250° C., preferably from 80 to 200° C., and to which no photoacid is added.
  • Another advantage of this buffer layer is that the uncontrollable crosslinking of a cationically crosslinkable semiconductor can be avoided by using the buffer layer, which for the first time permits controlled structuring of the semiconductor.
  • Yet another advantage of crosslinking the buffer layer is that the glass transition temperature of the material and therefore the stability of the layer are increased by the crosslinking.
  • the invention therefore relates to electronic devices containing at least one layer of a conductive doped polymer and at least one layer of an organic semiconductor, characterized in that at least one conducting or semiconducting organic buffer layer which is cationically polymerizable, and to which less than 0.5% of a photoacid is added, is introduced between these layers.
  • a photoacid is a compound which releases a protic acid by a photochemical reaction when exposed to actinic radiation.
  • photoacids are 4-(thio-phenoxyphenyl)-diphenylsulfonium hexafluoroantimonate or ⁇ 4-[(2-hydroxytetradecyl)-oxyl]-phenyl ⁇ -phenyliodonium hexafluoroantimonate and the like, as described for example in EP 1308781.
  • the photoacid may be added for the crosslinking reaction, in which case a proportion of from approximately 0.5 to approximately 3% by weight is preferably selected according to the prior art.
  • Electronic devices in the context of this invention are organic or polymeric light emitting diodes (OLEDs, PLEDs, for example EP 0676461, WO 98/27136), organic solar cells (O-SCs, for example WO 98/48433, WO 94/05045), organic field effect transistors (O-FETs, for example U.S. Pat. No. 5,705,826, U.S. Pat. No. 5,596,208, WO 00/42668), field quench elements (FQDs, for example US 2004/017148), organic circuit elements (O-ICs, for example WO 95/31833, WO 99/10939), organic optical amplifiers or organic laser diodes (O-lasers, WO 98/03566).
  • OLEDs organic or polymeric light emitting diodes
  • PLEDs for example EP 0676461, WO 98/27136
  • O-SCs organic solar cells
  • O-SCs for example WO 98/48433, WO 94/0504
  • Organic in the context of this invention means that at least one layer of an organic conductive doped polymer, at least one conducting or semiconducting organic buffer layer and at least one layer containing at least one organic semiconductor are present; further organic layers (for example electrodes) may also be present in addition to these. Moreover, layers which are not based on organic materials may also be present, for example inorganic interlayers or electrodes.
  • the electronic device is constructed from a substrate (conventionally glass or a plastic sheet), an electrode, an intermediate layer of a conductive doped polymer, a crosslinkable buffer layer according to the invention, an organic semiconductor and a back electrode.
  • This device is accordingly (depending on the application) structured, contacted and hermetically sealed, since the lifetime of such devices is drastically shortened in the presence of water and/or air. It may also be preferred to use a conductive doped polymer as the electrode material for one or both electrodes and not to introduce an interlayer of conductive doped polymer.
  • the structure also contains a further electrode (gate) which is separated from the organic semiconductor by an insulator layer generally having a high dielectric constant. It may furthermore be expedient to introduce yet other layers into the device.
  • the electrodes are selected so that their potential coincides as well as possible with the potential of the adjacent organic layer, in order to ensure maximally efficient electron or hole injection. If the cathode is to inject electrons, as is the case for example in OLEDs/PLEDs or n-type conducting O-FETs, or receive holes, as is the case for example in O-SCs, then metals with a low work function, metal alloys or multilayered structures comprising different metals, for example alkaline-earth metals, alkali metals, main group metals or lanthanides (for example Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.) are preferred for the cathode.
  • metals with a low work function metal alloys or multilayered structures comprising different metals, for example alkaline-earth metals, alkali metals, main group metals or lanthanides (for example Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.) are preferred for
  • the cathodes are conventionally between 10 and 10,000 nm, preferably between 20 and 1000 nm, thick. It may also be preferred to introduce a thin interlayer of a material having a high dielectric constant between a metal cathode and the organic semiconductor (or other functional organic layers which may optionally be present).
  • Alkali metal or alkaline-earth metal fluorides may for example be suitable for this (for example LiF, Li 2 O, BaF 2 , MgO, NaF, etc.).
  • the layer thickness of this dielectric layer is preferably between 1 and 10 nm.
  • the anode preferably has a potential of more than 4.5 eV vs. vacuum.
  • metals with a high redox potential are suitable for this, for example Ag, Pt or Au.
  • Metal/metal oxide electrodes for example Al/Ni/NiO x , Al/Pt/PtO x
  • the anode may also consist of a conductive organic material (for example a conductive doped polymer).
  • At least one of the electrodes must be transparent in order to allow either irradiation of the organic material (O-SCs) or output of light (OLEDs/PLEDs, O-lasers, organic optical amplifiers).
  • O-SCs organic material
  • O-lasers organic optical amplifiers
  • a preferred construction uses a transparent anode.
  • Preferred anode materials here are conductive mixed metal oxides. Indium-tin oxide (ITO) or indium-zinc oxide (IZO) are particularly preferred.
  • Conductive doped organic materials, in particular conductive doped polymers, are furthermore preferred.
  • a similar construction also applies to inverted structures, in which the light is output from the cathode or incident on the cathode.
  • the cathode then preferably consists of the materials described above, with the difference that the metal is very thin and therefore transparent.
  • the layer thickness of the cathode is preferably less than 50 nm, particularly preferably less than 30 nm, and in particular less than 10 nm.
  • a further transparent conductive material is applied thereon, for example indium-tin oxide (ITO), indium-zinc oxide (IZO) etc.
  • Various organic doped conductive polymers may be suitable for the conductive doped polymer (either as an electrode or as an additional charge injection layer or “Planarization Layer”, in order to compensate for unevennesses of the electrode and thus minimize short circuits).
  • the conductive doped polymer is applied onto the anode or functions directly as the anode.
  • the potential of the layer is preferably from 4 to 6 eV vs. vacuum.
  • the thickness of the layer is preferably between 10 and 500 nm, particularly preferably between 20 and 250 nm.
  • the layers are generally thicker in order to ensure a good outward electrical connection and a low capacitive impedance.
  • Derivatives of polythiophene are particularly preferably used (particularly preferably poly(ethylenedioxythiophene), PEDOT) and polyaniline (PANI).
  • the doping is generally carried out using acids or oxidizing agents.
  • the doping is preferably carried out using polymer-bound Brönsted acids.
  • polymer-bound sulfonic acids in particular poly(styrene sulfonic acid), poly(vinyl sulfonic acid) and PAMPSA (poly(2-acrylamido-2-methyl-propane sulfonic acid)) are particularly preferred for this.
  • the conductive polymer is generally applied from an aqueous solution or dispersion and is insoluble in organic solvents. The subsequent layer can thereby be readily applied from organic solvents.
  • Low molecular weight oligomeric, dendritic or polymeric semiconducting materials are in principle suitable for the organic semiconductor.
  • An organic material in the context of this invention is intended to mean not only purely organic materials, but also metallorganic materials and metal coordination compounds with organic ligands.
  • the oligomeric, dendritic or polymeric materials may be conjugated, non-conjugated or partially conjugated.
  • Conjugated polymers in the context of this invention are polymers which contain primarily sp 2 -hybridized carbon atoms in the main chain, which may also be replaced by corresponding heteroatoms. In the simplest case, this means the alternate presence of double and single bonds in the main chain.
  • conjugated polymer Primarily means that naturally occurring defects, which lead to conjugation interruptions, do not invalidate the term “conjugated polymer”.
  • conjugated likewise applies in this application text when the main chain contains for example arylamine units and/or particular heterocycles (i.e. conjugation via N, O or S atoms) and/or metallorganic complexes (i.e. conjugation via the metal atom).
  • Units such as, for example, simple alkene chains, (thio)ether bridges, ester, amide or imide linkages would however be unequivocally defined as non-conjugated segments.
  • conjugated organic material is also intended to include ⁇ -conjugated polysilanes, -germylenes and analogues which carry organic side groups, and can therefore be applied from organic solvents, for example poly(phenylmethylsilane).
  • Non-conjugated materials are materials in which no lengthy conjugated units occur in the main chain or in the dendrimer backbone.
  • partially conjugated materials is intended to mean those materials which have lengthy conjugated sections in the main chain or in the dendrimer backbone, which are bridged by non-conjugated units, or which contain lengthy conjugated units in the side chain.
  • conjugated polymers are poly-para-phenylenevinylene (PPV), polyfluorenes, polyspirobifluorenes or systems which are based in the broadest sense on poly-p-phenylene (PPP), and derivatives of the structures.
  • PPP poly-para-phenylenevinylene
  • PPP polyfluorenes
  • PPP polyspirobifluorenes or systems which are based in the broadest sense on poly-p-phenylene (PPP), and derivatives of the structures.
  • Materials with a high charge carrier mobility are primarily of interest for use in O-FETs. These are for example oligo- or poly(triarylamines), oligo- or poly(thiophenes) and copolymers which contain a large proportion of these units.
  • the layer thickness of the organic semiconductor is preferably 10-500 nm, particularly preferably 20-250 nm, depending on the application.
  • dendrimer is intended to mean a highly branched compound which is constructed from a multifunctional core to which branched monomers are bound in a regular structure, so that a tree-like structure is obtained. Both the core and the monomers may assume any branched structures which consist both of purely organic units and of organometallic compounds or coordination compounds.
  • dendrimers are to be understood as described for example in M. Fischer, F. Vögtle, Angew. Chem., Int. Ed. 1999, 38, 885-905.
  • crosslinkable organic layers have been developed (WO 02/10129). After the crosslinking reaction, these are insoluble and therefore can no longer be attacked by solvents during the application of further layers.
  • Crosslinkable organic semiconductors also have advantages for the structuring of multicolored PLEDs. The use of crosslinkable organic semiconductors is thus furthermore preferred.
  • Preferred crosslinking reactions are cationic polymerizations, based on electron-rich olefin derivatives, heteronuclear multiple bonds with heteroatoms or heterogroups or rings with heteroatoms (for example O, S, N, P, Si, etc.). Particularly preferred crosslinking reactions are cationic polymerizations based on rings with heteroatoms. Such crosslinking reactions are described in detail below for the buffer layer according to the invention.
  • Semiconducting luminescent polymers which can be chemically crosslinked are generally disclosed in WO 96/20253.
  • Oxetane-containing semiconducting polymers, as described in WO 02/10129, have proved particularly suitable. They can be crosslinked deliberately and in a controlled way by adding a photoacid and irradiation.
  • Crosslinkable low molecular weight compounds may furthermore be suitable, for example cationically crosslinkable triarylamines (M. S. Bayer et al., Macromol. Rapid Commun. 1999, 20, 224-228; D. C. Müller et al., Chem Phys Chem 2000, 207-211). These descriptions are incorporated into the present invention by reference.
  • the introduction of a buffer layer which is introduced between the conductive doped polymer and the organic semiconductor, and which carries the cationically crosslinkable units, is such that it can absorb low molecular weight cationic species and intrinsic cationic charge carriers which may diffuse out of the conductive doped polymer.
  • the buffer layer may be both low molecular weight and oligomeric, dendritic or polymeric.
  • the layer thickness is preferably in the range of 5-300 nm, particularly preferably in the range of 10-200 nm.
  • the potential of the layer preferably lies between the potential of the conductive doped polymer and that of the organic semiconductor. This can be achieved by a suitable choice of the materials for the buffer layer and suitable substitution of the materials.
  • Preferred materials for the buffer layer are derived from hole-conductive materials, such as those used as hole conductors in other applications.
  • Cationically crosslinkable triarylamine-based, thiophene-based or triarylphosphine-based materials or combinations of these systems are particularly preferably preferred for this.
  • Copolymers with other monomer units, for example fluorene, spirobifluorene, etc., with a high proportion of these hole-conductive units are also suitable. The potentials of these compounds can be adjusted by suitable substitution.
  • electron-withdrawing substituents for example F, Cl, CN, etc.
  • electron-repelling substituents for example alkoxy groups, amino groups, etc.
  • the buffer layer according to the invention may comprise low molecular weight compounds which are crosslinked in the layer and thus rendered insoluble. Oligomeric, dendritic or polymeric soluble solutions, which are rendered insoluble by subsequent cationic crosslinking, may also be suitable. Mixtures of low molecular weight compounds and oligomeric, dendritic and/or polymeric compounds may furthermore be used.
  • cationic species that can diffuse out of the conductive doped polymer are firstly protons which may originally come from the dopant being used (often polymer-bound sulfonic acids) but also ubiquitous water. Cationic species, for example metal ions, may also be present as (undesired) impurities in the conductive polymer.
  • cationic species is the electrode on which the conductive polymer is applied.
  • indium ions may emerge from an ITO electrode and diffuse into the active layers of the devices.
  • Other low molecular weight cationic species that may possibly be present are monomeric and oligomeric constituents of the conductive polymer, which are converted into a cationic state by protonation or by other doping. It is furthermore possible for charge carriers introduced by oxidative doping to diffuse into the semiconductor layer.
  • the cationically crosslinkable buffer layer can trap diffusing cationic species so that the crosslinking reaction is subsequently initiated; on the other hand, the buffer layer is simultaneously rendered insoluble by the crosslinking, so that the subsequent application of an organic semiconductor from conventional organic solvents presents no problems.
  • the crosslinked buffer layer represents a further barrier against diffusion.
  • Preferred cationically polymerizable groups of the buffer layer are the following functional groups:
  • Non-aromatic cyclic systems in which one or more ring atoms are identically or differently O, S, N, P, Si, etc., are generally suitable for this.
  • Cyclic systems having from 3 to 7 ring atoms, in which from 1 to 3 ring atoms are identically or differently O, S or N, are preferred.
  • Examples of such systems are unsubstituted or substituted cyclic amines (for example aziridine, azeticine, tetrahydropyrrole, piperidine), cyclic ethers (for example oxiran, oxetane, tetrahydrofuran, pyran, dioxane), as well as the corresponding sulfur derivatives, cyclic acetals (for example 1,3-dioxolane, 1,3-dioxepane, trioxane), lactones, cyclic carbonates, but also cyclic structures which contain different heteroatoms in the cycle, for example oxazolines, dihydrooxazines or oxazolones. Cyclic siloxanes having from 4 to 8 ring atoms are furthermore preferred.
  • low molecular weight, oligomeric or polymeric organic materials in which at least one H atom is replaced by a group of the formula (I), (II) or (III),
  • the crosslinking of these units is preferably carried out by thermal treatment of the device at this stage. It is not necessary, and not even desirable, to add a photoacid for the crosslinking since this would introduce impurities into the device. Without wishing to be bound by a special theory, we suspect that the crosslinking of the buffer layer is initiated by the protons emerging from the conductive doped polymer.
  • This crosslinking preferably takes place at a temperature of from 80 to 200° C. and for a duration of from 0.1 to 120 minutes, preferably from 1 to 60 minutes, particularly preferably from 1 to 10 minutes, in an inert atmosphere.
  • This crosslinking particularly preferably takes place at a temperature of from 100 to 180° C. and for a duration of from 20 to 40 minutes in an inert atmosphere.
  • auxiliaries which are not photoacids, but which can promote the crosslinking, to be added to the buffer layer.
  • Salts in particular inorganic salts, for example tetrabutylammonium hexafluoroantimonate, which are added as a supporting electrolyte in order to improve the crosslinking, acids, in particular organic acids, for example acetic acid, or further addition of polystyrene sulfonic acid to the conductive polymer, or oxidizing substances, for example nitrylium or nitrosylium salts (NO + , NO 2 + ), may for example be suitable for this.
  • auxiliaries can easily be washed out and therefore do not remain as contamination in the film.
  • the auxiliaries have the advantage that the crosslinking can thereby be fully carried out more easily and that thicker buffer layers can thereby also be produced.
  • this crosslinkable buffer layer which is introduced between the conductive doped polymer and the organic semiconductor, offers the following advantages:
  • the phases were separated and the process was repeated once more with 40 ml of the dithiocarbamate solution.
  • the phases were separated, the organic phase was washed with 3 ⁇ 150 ml of water and precipitated by adding it in two times the volume of methanol.
  • the raw polymer was dissolved in chlorobenzene, filtered using celite and precipitated by adding two times the volume of methanol. 1.84 g (64% Th.) of the polymer P2 were obtained, which is soluble in chlorobenzene but insoluble in toluene, THF or chloroform.
  • the LEDs were produced according to a general method which was adapted to the respective conditions (for example solution viscosity and optimal layer thickness of the functional layers in the device) in the particular case.
  • the LEDs described below were respectively three-layer systems (three organic layers), i.e. substrate//ITO//PEDOT//buffer layer//polymer//cathode.
  • PEDOT is a polythiophene derivative (Baytron P4083 from H. C. Stark, Goslar). Ba from Aldrich and Ag from Aldrich were used for the cathode in all cases.
  • the way in which PLEDs can generally be produced is described in detail in WO 04/037887 and the literature cited therein.
  • a cationically crosslinkable semiconductor was applied as a buffer layer on the PEDOT layer.
  • the crosslinkable polymers P1 and P2 or the crosslinkable low molecular weight compound V1 were used as materials for the buffer layer.
  • a solution (with a concentration of 4-25 mg/ml in for example toluene, chlorobenzene, xylene etc.) of the crosslinkable material was taken and dissolved by stirring at room temperature. Depending on the material, it may also be advantageous to stir for some time at 50-70° C. After the complete dissolving of the compound, it was filtered through a 5 ⁇ m filter.
  • the buffer layer was then spin coated at variable speeds (400-6000 rpm) with a spin coater in an inert atmosphere.
  • the layer thicknesses could thus be varied in a range of from approximately 20 to 300 nm.
  • the crosslinking was subsequently carried out by heating the device to 180° C. for 30 minutes on a hotplate in an inert atmosphere.
  • the organic semiconductor and the cathode were then applied onto the buffer layer, as described in WO 04/037887 and the literature cited therein.
  • the structured LEDs were produced similarly as Example 4 up to and including the step of crosslinking the buffer layer.
  • cationically crosslinkable semiconductors were used for the organic semiconductors. These were red, green and blue emitting conjugated polymers based on poly-spirobifluorene, which were functionalized with oxetane groups. These materials and their synthesis are already described in the literature ( Nature 2003, 421, 829).
  • a solution (generally with a concentration of 4-25 mg/ml in for example toluene, chlorobenzene, xylene:cyclohexanone (4:1)) was taken and dissolved by stirring at room temperature. Depending on the compound, it may also be advantageous to stir for some time at 50-70° C.
  • the film was then heat-treated in an inert atmosphere for 3 minutes at 130° C., subsequently treated with a 10 ⁇ 4 molar LiAlH 4 solution in THF and washed with THF.
  • the non-crosslinked positions in the film were thereby washed off.
  • This process was repeated with the other solutions of the crosslinkable organic semiconductors, and the three primary colors were thereby successively applied in a structured way.
  • the evaporation coating of the electrodes and the contacting were then carried out as described above.
  • the polymer exhibits a lifetime of approximately 500 h.
  • An LED was also produced whose buffer layer was photochemically crosslinked by adding 0.5% by weight of ⁇ 4-[(2-hydroxytetradecyl)-oxyl]-phenyl ⁇ -phenyliodonium hexafluoroantimonate with exposure to UV radiation (3 s, 302 nm) and subsequent heating to 90° C. for 30 seconds. The buffer layer was then washed with THF and heated to 180° C. for 5 minutes. Under otherwise equal conditions, this LED had a lifetime of approximately 630 h.
  • the measurement was repeated with polymer P2 as the buffer layer, as described in Example 6 under otherwise identical conditions.
  • the polymer exhibits a lifetime of approximately 1500 h without addition of photoacid to the buffer layer, and approximately 600 h with addition of photoacid.
  • the measurement was repeated with compound V1 as the buffer layer, as described in Example 6 under otherwise identical conditions.
  • the polymer exhibits a lifetime of approximately 1350 h without addition of photoacid to the buffer layer, and approximately 550 h with addition of photoacid.

Abstract

The present invention describes a novel design principle for organic electronic elements by inserting at least one additional crosslinkable layer. The properties of the electronic devices are thereby improved. Structured construction of these devices is furthermore facilitated.

Description

  • Electronic devices which contain organic, metallorganic or polymeric semiconductors, or compounds of more than one of these three groups, are more and more frequently being used in commercial products or are shortly to be introduced onto the market. Examples of existing commercial products include organic-based charge transport materials (generally triarylamine-based hole transporters) in copiers and organic or polymeric light emitting diodes (OLEDs or PLEDs) in display devices. Organic solar cells (O-SCs), organic field effect transistors (O-FETs), organic circuit elements (O-ICs) or organic laser diodes (O-lasers) are at a highly advanced research stage and could become very important in the future.
  • Irrespective of the intended purpose, many of these devices have the following general layer structure which is adapted accordingly for the individual applications:
      • (1) substrate
      • (2) contacting: conductive substance, electrode; often metallic or inorganic, but also of organic or polymeric conductive materials
      • (3) optionally charge injection layer or interlayer to compensate for unevennesses of the electrode (“Planarization Layer”), often of a conductive doped polymer
      • (4) organic semiconductor
      • (5) optionally insulating layer
      • (6) second contacting: as (2); second electrode, materials as mentioned in (2)
      • (7) interconnection
      • (8) encapsulation.
  • One advantage which many of these organic devices have, above all those which are based on polymeric or dendritic, or oligomeric semiconductors, is that they can be produced from solution which entails less technical and cost outlay than vacuum processes, as are generally carried out for low molecular weight compounds. For example, colored electroluminescent devices can be produced comparatively simply by processing the materials by surface coating from solution (for example by spin coating, doctor blade technique, etc.). The structuring, i.e. driving of individual image points, is usually carried out here in the “leads”, i.e. for example in the electrodes. This may, for example, be done using shadow masks in the manner of a template. The structuring of organic circuits and partially organic solar cell panels or laser arrays can be carried out similarly. For industrial mass production, however, this leads to significant disadvantages: after they have been used one or more times, the masks become unusable because of deposit formation, and must be elaborately regenerated. For production, it would therefore be desirable to have a process available for which shadow masks are not required.
  • Surface coating and structuring by shadow masks furthermore cannot be readily employed when, for example, full-color displays or organic circuits with different circuit elements are to be produced. For full-color displays, the three primary colors (red, green and, blue) in individual pixels (image points) must be applied next to one another with a high resolution. Similar considerations apply to electronic circuits with different circuit elements. While the individual image points can be produced by evaporating the individual colors using shadow masks in the case of low molecular weight evaporatable molecules (with the associated difficulties already mentioned above), this is not possible for polymeric materials and materials processed from solution, and the structuring can no longer be carried out merely by structuring the electrodes. An alternative in this case is to directly apply the active layer in a structured form (for example: the light emitting layer in OLEDs/PLEDs; similar considerations apply to lasers or charge transport layers in all applications). The fact that this presents considerable problems can be understood merely from the dimensions: it is necessary to provide structures in the range of a few tens of μm with layer thicknesses in the range of from less than 100 nm to a few μm. In particular, various printing techniques have recently been considered for this, for example inkjet printing, offset printing, etc. These printing techniques have their own problems, however, and none of them has yet been developed so that it might be usable for a mass production process. The aforementioned mask technology is furthermore used here (in the field of OLEDs) for the electrodes. Here again, this entails the aforementioned problems of deposit formation. Structurability by printing techniques must therefore still currently be regarded as an unresolved problem.
  • Another approach to structurability has been proposed in WO 02/10129 and Nature 2003, 421, 829. There, structurable materials are described which are suitable for use in structured devices such as OLEDs, PLEDs, organic lasers, organic circuit elements or organic solar cells. These are organic, in particular electroluminescent materials, which contain at least one oxetane group capable of crosslinking, the crosslinking reaction of which can be deliberately initiated and controlled. Macromol. Rapid Commun. 1999, 20, 225 describes N,N,N′,N′-tetraphenylbenzidines functionalized with oxetane groups, which can be crosslinked in a photoinduced way. These compound classes are used as structurable hole conductors directly on the anode of the organic electronic device. At least one photoinitiator is added to the materials for crosslinking. By exposure to actinic radiation, an acid is generated which initiates a crosslinking reaction by cationic ring-opening polymerization. A pattern of regions with crosslinked material and regions with uncrosslinked material can thus be obtained by structured exposure. The regions of uncrosslinked material can then be removed by suitable operations (for example washing with suitable solvents). This leads to the desired structuring. The subsequent application of the various layers (or other materials which are to be applied in proximity to the first material) can thus be carried out after the crosslinking is completed. Exposure, as employed for the structuring, is a standard process in modern electronics and can, for example, be carried out with lasers or by surface exposure using a suitable photomask. The mask does not involve the risk of deposition here, since in this case only radiation and no material flux has to be delimited by the mask. In Chem Phys Chem 2000, 207, such a crosslinked triarylamine layer is introduced as an interlayer between a conductive doped polymer and an organic luminescent semiconductor. A higher efficiency is obtained in this case. Here again, a photoacid is used for the crosslinking. This appears to be necessary for complete crosslinking of the triarylamine layer. However, the photoacid or its reaction products remain as contamination in the electronic device after the crosslinking. It is generally acknowledged that both organic and inorganic impurities can perturb the operation of organic electronic devices. For this reason, it would be desirable to be able to reduce the use of photoacids as much as possible.
  • EP 0637899 proposes electroluminescent arrangements having one or more layers in which at least one layer is obtained by thermal or radiation-induced crosslinking, which furthermore contain at least one emitter layer and at least one charge transport unit per layer. The crosslinking may take place radically, ionically, cationically or via a photoinduced ring closure reaction. An advantage mentioned is that a plurality of layers can thereby be formed on one another, or that the layers can also be structured in a radiation-induced way. However, no teaching is given as to which of the various crosslinking reactions can be used to produce a suitable device, and how the crosslinking reaction can best be carried out. It is merely mentioned that radically crosslinkable units or groups capable of photocycloaddition are preferred, that various types of auxiliaries, for example initiators, may be contained and that the film is preferably crosslinked by means of actinic radiation and not thermally. Suitable device configurations are also not described. It is therefore unclear how many layers the device preferably comprises, and how thick they should be, which material classes are preferably used and which of them should be crosslinked. It is therefore also not apparent to the person skilled in the art how the described invention can be successfully implemented in practice.
  • In devices for organic electronics, an interlayer of a conductive doped polymer is often introduced as a charge injection layer between the electrode (in particular the anode) and the function material (Appl. Phys. Lett. 1997, 70, 2067-2069).
  • Alternatively, a conductive doped polymer may also be used directly as the anode (or even as the cathode, depending on the application). The most common of these polymers are polythiophene derivatives (for example poly(ethylenedioxythiophene), PEDOT) and polyaniline (PANI), which are generally doped with polystyrene sulfonic acid or other polymer-bound Brönstedt acids and thus brought into a conductive state. Without wishing to be bound by the correctness of this special theory in the subsequent invention, we suspect that during operation of the device protons or other impurities diffuse from the acid groups into the functional layer where they are likely to perturb the functionality of the device significantly. It is thus suspected that these impurities reduce the efficiency as well as the lifetime of the devices. Protons or other cationic impurities have a negative effect in particular when the functional semiconductor layer applied onto this layer is cationically crosslinkable and, as described above, is intended to be structured. We suspect that the functional layer is already partially or fully crosslinked by the presence of protons or other cationic impurities, without providing the opportunity to control the crosslinking, for example by actinic radiation. The advantage of the controlled structurability is therefore lost. Cationically crosslinkable materials thus in principle do provide the possibility of structuring and therefore an alternative to printing techniques. However, technical implementation of these materials is not to date possible since the problem of uncontrolled crosslinking on a doped charge injection layer is not yet resolved.
  • Surprisingly, it has now been found that the electronic properties of the devices can be significantly improved when at least one buffer layer, which is cationically crosslinkable, is introduced between the doped interlayer and the functional organic semiconductor layer. Particularly good properties are obtained with a buffer layer whose cationic crosslinking is induced thermally, i.e. by a temperature rise to from 50 to 250° C., preferably from 80 to 200° C., and to which no photoacid is added. Another advantage of this buffer layer is that the uncontrollable crosslinking of a cationically crosslinkable semiconductor can be avoided by using the buffer layer, which for the first time permits controlled structuring of the semiconductor. Yet another advantage of crosslinking the buffer layer is that the glass transition temperature of the material and therefore the stability of the layer are increased by the crosslinking.
  • The invention therefore relates to electronic devices containing at least one layer of a conductive doped polymer and at least one layer of an organic semiconductor, characterized in that at least one conducting or semiconducting organic buffer layer which is cationically polymerizable, and to which less than 0.5% of a photoacid is added, is introduced between these layers.
  • It is preferable that no photoacid is added to the semiconducting organic buffer layer.
  • An organic buffer layer whose crosslinking in the corresponding device arrangement can be induced thermally, i.e. by a temperature rise to 50-250° C., preferably 80-200° C., without adding further auxiliaries, for example photoacids, is furthermore preferred.
  • A photoacid is a compound which releases a protic acid by a photochemical reaction when exposed to actinic radiation. Examples of photoacids are 4-(thio-phenoxyphenyl)-diphenylsulfonium hexafluoroantimonate or {4-[(2-hydroxytetradecyl)-oxyl]-phenyl}-phenyliodonium hexafluoroantimonate and the like, as described for example in EP 1308781. The photoacid may be added for the crosslinking reaction, in which case a proportion of from approximately 0.5 to approximately 3% by weight is preferably selected according to the prior art.
  • Electronic devices in the context of this invention are organic or polymeric light emitting diodes (OLEDs, PLEDs, for example EP 0676461, WO 98/27136), organic solar cells (O-SCs, for example WO 98/48433, WO 94/05045), organic field effect transistors (O-FETs, for example U.S. Pat. No. 5,705,826, U.S. Pat. No. 5,596,208, WO 00/42668), field quench elements (FQDs, for example US 2004/017148), organic circuit elements (O-ICs, for example WO 95/31833, WO 99/10939), organic optical amplifiers or organic laser diodes (O-lasers, WO 98/03566). Organic in the context of this invention means that at least one layer of an organic conductive doped polymer, at least one conducting or semiconducting organic buffer layer and at least one layer containing at least one organic semiconductor are present; further organic layers (for example electrodes) may also be present in addition to these. Moreover, layers which are not based on organic materials may also be present, for example inorganic interlayers or electrodes.
  • In the simplest case, the electronic device is constructed from a substrate (conventionally glass or a plastic sheet), an electrode, an intermediate layer of a conductive doped polymer, a crosslinkable buffer layer according to the invention, an organic semiconductor and a back electrode. This device is accordingly (depending on the application) structured, contacted and hermetically sealed, since the lifetime of such devices is drastically shortened in the presence of water and/or air. It may also be preferred to use a conductive doped polymer as the electrode material for one or both electrodes and not to introduce an interlayer of conductive doped polymer. For applications in O-FETs, in addition to the electrode and the back electrode (source and drain), it is furthermore necessary that the structure also contains a further electrode (gate) which is separated from the organic semiconductor by an insulator layer generally having a high dielectric constant. It may furthermore be expedient to introduce yet other layers into the device.
  • The electrodes are selected so that their potential coincides as well as possible with the potential of the adjacent organic layer, in order to ensure maximally efficient electron or hole injection. If the cathode is to inject electrons, as is the case for example in OLEDs/PLEDs or n-type conducting O-FETs, or receive holes, as is the case for example in O-SCs, then metals with a low work function, metal alloys or multilayered structures comprising different metals, for example alkaline-earth metals, alkali metals, main group metals or lanthanides (for example Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.) are preferred for the cathode. For multilayered structures, in addition to the aforementioned metals it is also possible to use other metals which have a relatively high work function, for example Ag, in which case combinations of the metals are generally used, for example Ca/Ag or Ba/Ag. The cathodes are conventionally between 10 and 10,000 nm, preferably between 20 and 1000 nm, thick. It may also be preferred to introduce a thin interlayer of a material having a high dielectric constant between a metal cathode and the organic semiconductor (or other functional organic layers which may optionally be present). Alkali metal or alkaline-earth metal fluorides, or alternatively the corresponding oxides, may for example be suitable for this (for example LiF, Li2O, BaF2, MgO, NaF, etc.). The layer thickness of this dielectric layer is preferably between 1 and 10 nm.
  • Materials with a high work function are preferred for the anode when holes are injected (as for example in OLEDs/PLEDs, p-type conducting O-FETs) or electrons are received (as for example O-SCs) at the anode. The anode preferably has a potential of more than 4.5 eV vs. vacuum. On the one hand, metals with a high redox potential are suitable for this, for example Ag, Pt or Au. Metal/metal oxide electrodes (for example Al/Ni/NiOx, Al/Pt/PtOx) may also be preferred. The anode may also consist of a conductive organic material (for example a conductive doped polymer).
  • For some applications, at least one of the electrodes must be transparent in order to allow either irradiation of the organic material (O-SCs) or output of light (OLEDs/PLEDs, O-lasers, organic optical amplifiers). A preferred construction uses a transparent anode. Preferred anode materials here are conductive mixed metal oxides. Indium-tin oxide (ITO) or indium-zinc oxide (IZO) are particularly preferred. Conductive doped organic materials, in particular conductive doped polymers, are furthermore preferred. A similar construction also applies to inverted structures, in which the light is output from the cathode or incident on the cathode. The cathode then preferably consists of the materials described above, with the difference that the metal is very thin and therefore transparent. The layer thickness of the cathode is preferably less than 50 nm, particularly preferably less than 30 nm, and in particular less than 10 nm. A further transparent conductive material is applied thereon, for example indium-tin oxide (ITO), indium-zinc oxide (IZO) etc.
  • Various organic doped conductive polymers may be suitable for the conductive doped polymer (either as an electrode or as an additional charge injection layer or “Planarization Layer”, in order to compensate for unevennesses of the electrode and thus minimize short circuits). Polymers which have a conductivity of >10−8 S/cm, depending on the application, are preferred here. In a preferred embodiment of this invention, the conductive doped polymer is applied onto the anode or functions directly as the anode. Here, the potential of the layer is preferably from 4 to 6 eV vs. vacuum. The thickness of the layer is preferably between 10 and 500 nm, particularly preferably between 20 and 250 nm. If the conductive doped polymer itself is the electrode, then the layers are generally thicker in order to ensure a good outward electrical connection and a low capacitive impedance. Derivatives of polythiophene are particularly preferably used (particularly preferably poly(ethylenedioxythiophene), PEDOT) and polyaniline (PANI). The doping is generally carried out using acids or oxidizing agents. The doping is preferably carried out using polymer-bound Brönsted acids. Generally polymer-bound sulfonic acids, in particular poly(styrene sulfonic acid), poly(vinyl sulfonic acid) and PAMPSA (poly(2-acrylamido-2-methyl-propane sulfonic acid)) are particularly preferred for this. The conductive polymer is generally applied from an aqueous solution or dispersion and is insoluble in organic solvents. The subsequent layer can thereby be readily applied from organic solvents.
  • Low molecular weight oligomeric, dendritic or polymeric semiconducting materials are in principle suitable for the organic semiconductor. An organic material in the context of this invention is intended to mean not only purely organic materials, but also metallorganic materials and metal coordination compounds with organic ligands. The oligomeric, dendritic or polymeric materials may be conjugated, non-conjugated or partially conjugated. Conjugated polymers in the context of this invention are polymers which contain primarily sp2-hybridized carbon atoms in the main chain, which may also be replaced by corresponding heteroatoms. In the simplest case, this means the alternate presence of double and single bonds in the main chain. Primarily means that naturally occurring defects, which lead to conjugation interruptions, do not invalidate the term “conjugated polymer”. Furthermore, the term conjugated likewise applies in this application text when the main chain contains for example arylamine units and/or particular heterocycles (i.e. conjugation via N, O or S atoms) and/or metallorganic complexes (i.e. conjugation via the metal atom). Units such as, for example, simple alkene chains, (thio)ether bridges, ester, amide or imide linkages would however be unequivocally defined as non-conjugated segments. Furthermore, the term conjugated organic material is also intended to include σ-conjugated polysilanes, -germylenes and analogues which carry organic side groups, and can therefore be applied from organic solvents, for example poly(phenylmethylsilane). Non-conjugated materials are materials in which no lengthy conjugated units occur in the main chain or in the dendrimer backbone. The term partially conjugated materials is intended to mean those materials which have lengthy conjugated sections in the main chain or in the dendrimer backbone, which are bridged by non-conjugated units, or which contain lengthy conjugated units in the side chain. Typical examples of conjugated polymers, as may for example be used in PLEDs or O-SCs, are poly-para-phenylenevinylene (PPV), polyfluorenes, polyspirobifluorenes or systems which are based in the broadest sense on poly-p-phenylene (PPP), and derivatives of the structures. Materials with a high charge carrier mobility are primarily of interest for use in O-FETs. These are for example oligo- or poly(triarylamines), oligo- or poly(thiophenes) and copolymers which contain a large proportion of these units.
  • The layer thickness of the organic semiconductor is preferably 10-500 nm, particularly preferably 20-250 nm, depending on the application.
  • Here, the term dendrimer is intended to mean a highly branched compound which is constructed from a multifunctional core to which branched monomers are bound in a regular structure, so that a tree-like structure is obtained. Both the core and the monomers may assume any branched structures which consist both of purely organic units and of organometallic compounds or coordination compounds. Here, dendrimers are to be understood as described for example in M. Fischer, F. Vögtle, Angew. Chem., Int. Ed. 1999, 38, 885-905.
  • In order to be able to apply a plurality of organic semiconductors above one another from solution, which is advantageous for many optoelectronic applications (for example PLEDs), crosslinkable organic layers have been developed (WO 02/10129). After the crosslinking reaction, these are insoluble and therefore can no longer be attacked by solvents during the application of further layers. Crosslinkable organic semiconductors also have advantages for the structuring of multicolored PLEDs. The use of crosslinkable organic semiconductors is thus furthermore preferred. Preferred crosslinking reactions are cationic polymerizations, based on electron-rich olefin derivatives, heteronuclear multiple bonds with heteroatoms or heterogroups or rings with heteroatoms (for example O, S, N, P, Si, etc.). Particularly preferred crosslinking reactions are cationic polymerizations based on rings with heteroatoms. Such crosslinking reactions are described in detail below for the buffer layer according to the invention.
  • Semiconducting luminescent polymers which can be chemically crosslinked are generally disclosed in WO 96/20253. Oxetane-containing semiconducting polymers, as described in WO 02/10129, have proved particularly suitable. They can be crosslinked deliberately and in a controlled way by adding a photoacid and irradiation. Crosslinkable low molecular weight compounds may furthermore be suitable, for example cationically crosslinkable triarylamines (M. S. Bayer et al., Macromol. Rapid Commun. 1999, 20, 224-228; D. C. Müller et al., Chem Phys Chem 2000, 207-211). These descriptions are incorporated into the present invention by reference.
  • Without wishing to be bound by a particular theory, we suspect that hydrogen atoms or other cationic impurities contained in the conductive doped polymer can already initiate a cationic polymerization when a cationically crosslinkable semiconductor is applied thereon, and therefore make the latter impossible to structure. But even layers of organic semiconductors, which are not cationically crosslinkable, on conductive doped polymers are problematic since impurities and their diffusion out of the doped polymer are likely to limit the lifetime of the electronic device. Furthermore, the hole injection out of the doped polymer into the organic semiconductor is often unsatisfactory.
  • According to the invention, therefore, the introduction of a buffer layer which is introduced between the conductive doped polymer and the organic semiconductor, and which carries the cationically crosslinkable units, is such that it can absorb low molecular weight cationic species and intrinsic cationic charge carriers which may diffuse out of the conductive doped polymer. Before the crosslinking, the buffer layer may be both low molecular weight and oligomeric, dendritic or polymeric. The layer thickness is preferably in the range of 5-300 nm, particularly preferably in the range of 10-200 nm. The potential of the layer preferably lies between the potential of the conductive doped polymer and that of the organic semiconductor. This can be achieved by a suitable choice of the materials for the buffer layer and suitable substitution of the materials.
  • Preferred materials for the buffer layer are derived from hole-conductive materials, such as those used as hole conductors in other applications. Cationically crosslinkable triarylamine-based, thiophene-based or triarylphosphine-based materials or combinations of these systems are particularly preferably preferred for this. Copolymers with other monomer units, for example fluorene, spirobifluorene, etc., with a high proportion of these hole-conductive units are also suitable. The potentials of these compounds can be adjusted by suitable substitution. By the introduction of electron-withdrawing substituents (for example F, Cl, CN, etc.) for instance, it is possible to achieve compounds with a low HOMO (=highest occupied molecular orbital), while a high HOMO can be achieved by introduction of electron-repelling substituents (for example alkoxy groups, amino groups, etc.).
  • The buffer layer according to the invention may comprise low molecular weight compounds which are crosslinked in the layer and thus rendered insoluble. Oligomeric, dendritic or polymeric soluble solutions, which are rendered insoluble by subsequent cationic crosslinking, may also be suitable. Mixtures of low molecular weight compounds and oligomeric, dendritic and/or polymeric compounds may furthermore be used. Without wishing to be bound by a special theory in this invention, cationic species that can diffuse out of the conductive doped polymer are firstly protons which may originally come from the dopant being used (often polymer-bound sulfonic acids) but also ubiquitous water. Cationic species, for example metal ions, may also be present as (undesired) impurities in the conductive polymer. Another possible source of cationic species is the electrode on which the conductive polymer is applied. For example, indium ions may emerge from an ITO electrode and diffuse into the active layers of the devices. Other low molecular weight cationic species that may possibly be present are monomeric and oligomeric constituents of the conductive polymer, which are converted into a cationic state by protonation or by other doping. It is furthermore possible for charge carriers introduced by oxidative doping to diffuse into the semiconductor layer. The cationically crosslinkable buffer layer can trap diffusing cationic species so that the crosslinking reaction is subsequently initiated; on the other hand, the buffer layer is simultaneously rendered insoluble by the crosslinking, so that the subsequent application of an organic semiconductor from conventional organic solvents presents no problems. The crosslinked buffer layer represents a further barrier against diffusion.
  • Preferred cationically polymerizable groups of the buffer layer are the following functional groups:
    • 1) electron-rich olefin derivatives,
    • 2) heteronuclear multiple bonds with heteroatoms or heterogroups, or
    • 3) rings with heteroatoms (for example O, S, N, P, Si, etc.), which react by cationic ring-opening polymerization.
  • Organic materials which carry at least one substituent that reacts by cationic ring-opening polymerization are preferred. A general review of cationic ring-opening polymerization is given, for example, by E. J. Goethals et al., “Cationic Ring Opening Polymerization” (New Methods Polym. Synth. 1992, 67-109). Non-aromatic cyclic systems, in which one or more ring atoms are identically or differently O, S, N, P, Si, etc., are generally suitable for this.
  • Cyclic systems having from 3 to 7 ring atoms, in which from 1 to 3 ring atoms are identically or differently O, S or N, are preferred. Examples of such systems are unsubstituted or substituted cyclic amines (for example aziridine, azeticine, tetrahydropyrrole, piperidine), cyclic ethers (for example oxiran, oxetane, tetrahydrofuran, pyran, dioxane), as well as the corresponding sulfur derivatives, cyclic acetals (for example 1,3-dioxolane, 1,3-dioxepane, trioxane), lactones, cyclic carbonates, but also cyclic structures which contain different heteroatoms in the cycle, for example oxazolines, dihydrooxazines or oxazolones. Cyclic siloxanes having from 4 to 8 ring atoms are furthermore preferred.
  • More particularly preferred are low molecular weight, oligomeric or polymeric organic materials in which at least one H atom is replaced by a group of the formula (I), (II) or (III),
    Figure US20070034862A1-20070215-C00001
      • in which
      • R1 in each occurrence is identically or differently hydrogen, a straight-chained, branched or cyclic alkyl, alkoxy or thioalkoxy group having from 1 to 20 C atoms, an aromatic or heteroaromatic ring system having from 4 to 24 aromatic ring atoms or an alkenyl group having from 2 to 10 C atoms, wherein one or more hydrogen atoms may be replaced by halogen such as Cl and F or by CN and one or more non-neighboring C atoms may be replaced by —O—, —S—, —CO—, —COO— or —O—CO—; a plurality of R1 radicals may also form a mono- or polycyclic, aliphatic or aromatic ring system with one another or with R2, R3 and/or R4;
      • R2 in each occurrence is identically or differently hydrogen, a straight-chained, branched or cyclic alkyl group having from 1 to 20 C atoms, an aromatic or heteroaromatic ring system having from 4 to 24 aromatic ring atoms or an alkenyl group having from 2 to 10 C atoms, wherein one or more hydrogen atoms may be replaced by halogen such as Cl and F or by CN and one or more non-neighboring C atoms may be replaced by —O—, —S—, —CO—, —COO—or —O—CO—; a plurality of R2 radicals may also form a mono- or polycyclic, aliphatic or aromatic ring system with one another or with R1, R3 and/or R4;
      • X in each occurrence is identically or differently —O—, —S—, —CO—, —COO—, —O—CO— or a bivalent —(CR3R4)n— group;
      • Z in each occurrence is identically or differently a bivalent —(CR3R4)n— group;
      • R3, R4 in each occurrence is identically or differently hydrogen, a straight-chained, branched or cyclic alkyl, alkoxy or thioalkoxy group having from 1 to 20 C atoms, an aromatic or heteroaromatic ring system having from 4 to 24 aromatic ring atoms or an alkenyl group having from 2 to 10 C atoms, wherein one or more hydrogen atoms may be replaced by halogen such as Cl and F or by CN; two or more R3 or R4 radicals may also form a ring system with one another or with R1 or R2;
      • n in each occurrence is identically or differently an integer between 0 and 20, preferably between 1 and 10, in particular between 1 and 6;
        with the proviso that the number of these groups according to formula (I) and/or formula (II) and/or formula (III) is limited by the maximally available, i.e. substitutable H atoms.
  • The crosslinking of these units is preferably carried out by thermal treatment of the device at this stage. It is not necessary, and not even desirable, to add a photoacid for the crosslinking since this would introduce impurities into the device. Without wishing to be bound by a special theory, we suspect that the crosslinking of the buffer layer is initiated by the protons emerging from the conductive doped polymer. This crosslinking preferably takes place at a temperature of from 80 to 200° C. and for a duration of from 0.1 to 120 minutes, preferably from 1 to 60 minutes, particularly preferably from 1 to 10 minutes, in an inert atmosphere. This crosslinking particularly preferably takes place at a temperature of from 100 to 180° C. and for a duration of from 20 to 40 minutes in an inert atmosphere. For the crosslinking, it may also be advantageous for further auxiliaries which are not photoacids, but which can promote the crosslinking, to be added to the buffer layer. Salts, in particular inorganic salts, for example tetrabutylammonium hexafluoroantimonate, which are added as a supporting electrolyte in order to improve the crosslinking, acids, in particular organic acids, for example acetic acid, or further addition of polystyrene sulfonic acid to the conductive polymer, or oxidizing substances, for example nitrylium or nitrosylium salts (NO+, NO2 +), may for example be suitable for this. After the crosslinking has been carried out, these auxiliaries can easily be washed out and therefore do not remain as contamination in the film. The auxiliaries have the advantage that the crosslinking can thereby be fully carried out more easily and that thicker buffer layers can thereby also be produced.
  • The following general method, which can be adapted appropriately to the particular case without any further inventive step, is in general employed for production of the devices:
      • A substrate (for example glass or a plastic) is coated with the anode (for example indium-tin oxide ITO, etc.). The anode is subsequently (for example photolithographically) structured and interconnected according to the intended application. In this case, the entire substrate and the corresponding interconnection may first be produced using a quite elaborate process so as to facilitate so-called active matrix control. The pre-cleaned substrate coated with the anode is treated either with ozone or with oxygen plasma or briefly exposed to an excimer lamp.
      • A conductive polymer, for example a doped polythiophene derivative (PEDOT) or polyaniline derivative (PANI) is subsequently applied in a thin layer, usually with a layer thickness of between 10 and 500 nm, preferably between 20 and 300 nm, onto the ITO substrate by spin coating or other coating methods.
      • The cationically crosslinkable buffer layer according to the invention is applied onto this layer. To this end, the corresponding compound is first dissolved in a solvent or solvent mixture and filtered. Since organic semiconductors and above all the surfaces of the layers are sometimes extremely influenced by oxygen or other air constituents, it is recommended to carry out this operation under a protective gas. Aromatic liquids, for example toluene, xylene, anisole, chlorobenzene and the like, for example cyclic ethers (for example, dioxane, methyldioxane, THF), as well as amides, for example NMP or DMF, but also solvent mixtures as described in application text WO 02/072714, are suitable as solvents for aromatic compounds. Other organic solvents, which are selected as a function of the compound class used, are also suitable for low molecular weight compounds. Using these solutions, the previously coated support can be coated or covered surface-wide, for example by spin-coating methods, flow or wave coating or doctor blade techniques. The crosslinking of the buffer layer can take place by heating the device at this stage in an inert atmosphere. Here, it is not necessary and not even desirable to add a photoacid; thermal treatment of the buffer layer on the doped polymer is sufficient in order to carry out the crosslinking reaction. Optionally, it may subsequently be flushed with a solvent, for example THF. It is then optionally dried.
      • A solution of an organic semiconductor is then applied. The choice of the semiconductor depends on the intended application. If a crosslinkable organic semiconductor is used, this may be structured according to the intended application by controlled crosslinking. In the case of cationically crosslinkable semiconductors, for example, this may be done by adding a photoacid, exposure through a shadow mask and subsequent thermal treatment. Since the underlying buffer layer is not acidic, the use of a photoacid should not be ruled out here. The uncrosslinked part of the semiconductor may subsequently be washed with an organic solvent in which the semiconductor is soluble. This process can be repeated for different materials, so as to successively apply a plurality of materials in a structured way. For example, electroluminescent polymers with different emission colors may be successively applied in a structured way for a full-color display, or organic field effect transistors with different functions may be successively applied for organic circuits. It is also possible to apply a plurality of crosslinkable layers above one another.
      • Further functional layers, for example charge injection or transport layers, further emission layers and/or hole blocking layers may optionally be applied on these polymer layers, for example from solution by methods such as those described for the buffer layer, but also by evaporation.
      • A cathode is subsequently applied. This is carried out according to the prior art by a vacuum process and may, for example, be done by thermal evaporation or plasma spraying (sputtering). The cathode may be applied surface-wide or using a mask so that it is structured. The contacting of the electrodes is then carried out.
      • Since many applications react sensitively to water, hydrogen or other constituents of the atmosphere, effective encapsulation of the device is indispensable.
      • The structure described above is adapted accordingly for the individual applications and can generally be used for different applications, such as organic and polymeric light emitting diodes, organic solar cells, organic field effect transistors, organic circuit elements, organic optical amplifiers or organic laser diodes.
  • Surprisingly, this crosslinkable buffer layer, which is introduced between the conductive doped polymer and the organic semiconductor, offers the following advantages:
      • 1) Introducing the crosslinkable buffer layer according to the invention improves the optoelectronic properties of the electronic device compared with a device which does not contain such a buffer layer. For instance, a high efficiency and a longer lifetime with a reduced operating voltage are observed. It turns out that this effect is particularly pronounced when the crosslinking of the buffer layer is thermally initiated. If a photoacid is added to the buffer layer for crosslinking, as described in the literature, the lifetime remains virtually unchanged.
      • 2) Since the buffer layer probably traps cationic species which emerge from the conductive doped polymer, they are prevented from diffusing into the organic semiconductor. If the organic semiconductor is a cationically crosslinkable compound, then undesired crosslinking of the semiconductor is thereby avoided. This for the first time allows controlled structuring of the semiconductor, which has not previously been possible in this way.
  • The present invention will be explained in more detail by the following examples, which are not meant to restrict it. Only organic and polymeric light emitting diodes will be discussed in these examples. Without any inventive step, however, the person skilled in the art will be able to produce other electronic devices on the basis of the examples given, for example O-SCs, O-FETs, O-ICs, optical amplifiers and O-lasers, to mention only a few further applications.
  • EXAMPLES Example 1 Synthesis of a Cationically Crosslinkable Compound P1 for Use as a Buffer Layer a) Synthesis of Precursors Known from the Literature
  • 3-Ethyl-3-(iodomethyl)oxetane (WO 96/21657), 11-(4-bromophenoxy)-1-undecanol (M. Trollsaas et al., Macromol. Chem. Phys. 1996, 197, 767-779) and N,N′-diphenylbenzidine (K. Wiechert et al., Zeitschrift Chem. 1975, 15, 49-50) were synthesized according to the literature.
  • b) Synthesis of N,N′-Bis-(4-bromophenyl)-N,N′-bis-(4-tert-butylphenyl)-biphenyl-4,4′-diamine (monomer M1)
  • Figure US20070034862A1-20070215-C00002
  • The synthesis of monomer M1 is described in WO 02/077060.
  • c) Synthesis of N,N′-Bis-(4-pinacol boronate)phenyl-N,N′-bis-(4-tert-butylphenyl)-biphenyl-4,4′-diamine (monomer M2)
  • Figure US20070034862A1-20070215-C00003
  • The synthesis of monomer M2 is described in application DE 10337077.3 which has not yet been laid open.
  • d) Synthesis of 3-(11-(4-bromophenoxy)-undecan-1-oxy)methylene-3-ethyl-oxetane
  • Figure US20070034862A1-20070215-C00004
  • 1.6 g (30 mmol) of NaH were suspended in 70 ml of dry DMF and stirred under a protective gas. A solution of 6.8 g (20 mmol) 11-(4-Bromophenoxy)-1-undecanol in 25 ml of DMF was added thereto at 40° C. After 1 h, 2.96 g (22 mmol) of 3-ethyl-3-(iodomethyl)oxetane and 0.166 g (1.0 mmol) of KI were added and stirred for 24 h at 40° C. After cooling to room temperature, 200 ml of water and 200 ml of CH2Cl2 were added to the reaction mixture, the organic phase was separated, dried over Mg2SO4 and the solvent was removed in a vacuum. The product was purified chromatographically (silica, eluent hexane). The yield was 3.2 g (89% Th.) and the purity was 98% (according to HPLC).
  • 1H-NMR (CDCl3, 500 MHz): 1.45 (t, J=7.3 Hz, 3H), 1.45 (m, 14H), 1.55 (m, 2H), 1.75 (m, 4H), 3.42 (t, J=6.3 Hz, 2H), 3.46 (s, 2H), 3.85 (t, J=6.3 Hz, 2H), 4.39 (d, J=5.9 Hz, 2H), 4.44 (d, J=5.9 Hz, 2H), 6.75 (d, J=9 Hz, 2H), 7.35 (d, J=9 Hz, 2H).
  • e) Synthesis of oxetane-substituted N,N,N′,N′-tetraphenylbenzidine
  • Figure US20070034862A1-20070215-C00005
  • A degassed solution of 5.1 g (9.7 mmol) N,N′-diphenylbenzidine and 14 g (21.4 mmol) 3-(11-(4-bromophenoxy)-undecan-1-oxy)methylene-3-ethyl-oxetane in 250 ml of toluene was saturated for 1 h with N2. First 0.12 g (0.39 mmol) of P(tBu)3 then 69 mg (0.19 mmol) of Pd(OAc)2 were added to the solution. 3.8 g (50.4 mmol) of solid NaOtBu were subsequently added. The reaction mixture was heated for 5 h under reflux. After cooling to room temperature, 0.85 g NaCN and 10 ml of water were added. The organic phase was washed with 4×50 ml of H2O, dried over MgSO4 and the solvent was removed in a vacuum. The pure product was obtained by recrystallization from dioxane with a purity of 99.2% (according to HPLC). The yield was 12 g (75% Th.).
  • 1H-NMR (CDCl3, 500 MHz): 0.81 (t, J=7.3 Hz, 6H), 1.17 (t, J=7.0 Hz, 12H), 1.23-1.35 (m, 28H), 3.94 (t, J=6.3 Hz, 4H), 4.03 (t, J=6.3 Hz, 8H), 4.21 (d, J=5.9 Hz, 4H), 4.29 (d, J=5.9 Hz, 4H), 6.91-7.01 (m, 14H), 7.04 (d, J=9 Hz, 4H), 7.27 (d, J=8 Hz, 4H), 7.49 (d, J=8.7 Hz, 4H).
  • f) Synthesis of oxetane-substituted, brominated N,N,N′,N′-tetraphenylbenzidine (monomer M3)
  • Figure US20070034862A1-20070215-C00006
  • 45.72 g (43.7 mmol) of oxetane-substituted N,N,N′,N′-tetraphenylbenzidine were prepared in 500 ml of THF. A solution of 15.15 g (84.4 mmol) NBS in 300 ml of THF was added drop-wise thereto at 0° C. while excluding light. It was allowed to reach RT and stirred for a further 4 h. 500 ml of water were added, and the mixture was extracted with CH2Cl2. The organic phase was dried over MgSO4 and the solvent was removed in a vacuum. The product was hot extracted by stirring with hexane and suctioned. After repeated chromatographic purification (silica, hexane/ethyl acetate 4:1), the product was obtained with a yield of 44 g (85% Th.) as a pale brown oil which had a purity of 99.2% (according to HPLC).
  • 1H-NMR (DMSO-d6, 500 MHz): 0.81 (t, J=7.3 Hz, 6H), 1.17 (t, J=7.0 Hz, 12H), 1.23-1.35 (m, 28H), 3.94 (t, J=6.3 Hz, 4H), 4.03 (t, J=6.3 Hz, 8H), 4.21 (d, J=5.9 Hz, 4H), 4.29 (d, J=5.9 Hz, 4H), 6.91-7.02 (m, 12H), 7.04 (d, J=9 Hz, 4H), 7.29 (d, J=8 Hz, 4H), 7.51 (d, J=8.7 Hz, 4H).
  • g) Polymer synthesis: Synthesis of Polymer P1
  • 1.7056 g (2 mmol) of monomer M2, 0.9104 g (1.2 mmol) of monomer M1, 0.9723 g (0.8 mmol) of monomer M3 and 2.03 g (4.4 mmol) of hydrated potassium phosphate were dissolved in 12.5 ml of toluene, 12.5 ml of dioxane and 12 ml of water (all the solvents free of oxygen) and degassed at 40° C. for 30 minutes with an argon stream. 0.90 mg of Pd(OAc)2 and 6.30 mg of P(o-tol)3 were added as a catalyst, and the reaction mixture was heated for 3 h under reflux. 20 ml of toluene and as an end capper 12 mg (0.04 mmol) of 3,4-bispentoxybenzeneboronic acid were added, heated for 1 h under reflux, then 20 mg (0.06 mmol) of 3,4-bispentoxybenzene bromide were added and heated for 1 h under reflux. The reaction solution was cooled to 65° C. and extracted by stirring for 4 h with 10 ml of 5% strength aqueous sodium N,N-diethyidithiocarbamate solution. The organic phase was washed with 3×80 ml of water and precipitated by adding it in two times the volume of methanol. The raw polymer was dissolved in chlorobenzene, filtered using celite and precipitated by adding two times the volume of methanol. 2.24 g (78% Th.) of the polymer P1 were obtained.
  • Example 2 Synthesis of a Cationically Crosslinkable Polymer P2 for use as a Buffer Layer a) Synthesis of bis-(4-bromophenyl)-(4-secbutylphenyl)-amine (monomer M4)
  • Figure US20070034862A1-20070215-C00007
  • The synthesis of M4 was carried out in analogy with the synthesis in DE 19981010.
  • b) Synthesis of Bis-((4-pinacole boronate)phenyl)-(4-secbutylphenyl)-amine (monomer M5)
  • Figure US20070034862A1-20070215-C00008
  • The synthesis of monomer M5 is described in application DE 10337077.3 which has not yet been laid open.
  • c) Synthesis of 2,7-dibromo-(2,5-dimethylphenyl)-9-(3,4-di(3-ethyl(oxetane-3-ethyloxy)-hexyloxyphenyl))-fluorene (monomer M6)
  • Figure US20070034862A1-20070215-C00009
  • The synthesis of monomer M6 is described in C. D. Müller et al., Nature 2003, 421, 829.
  • d) Polymer synthesis: Synthesis of Polymer P2
  • 1.4695 g (3.2 mmol) of monomer M4, 2.2134 g (4 mmol) of monomer M5, 0.7463 g (0.8 mmol) of monomer M6 and 4.05 g (8.8 mmol) of hydrated potassium phosphate were dissolved in 25 ml of toluene, 25 ml of dioxane and 25 ml of water (all solvents free of oxygen) and degassed at 40° C. for 30 minutes in an argon stream. 1.80 mg of Pd(OAc)2 and 14.61 mg of P(o-tol)3 were then added, and the reaction mixture was heated for 10 h under reflux. The initial amounts of Pd(OAc)2 and P(o-tol)3 were respectively added after 4 h, after 5.5 h and after 8.5 h. 2 ml of toluene were added after a reaction time of 8 h. 24 mg (0.08 mmol) of 3,4-bispentoxybenzolboronic acid were added as an end capper, heated for 2 h under reflux, then 40 mg (0.12 mmol) of 3,4-bispentoxybenzenebromide were added and heated for 1 h under reflux. The reaction solution was cooled to 65° C. and then extracted by stirring for 4 h with 20 ml of a 5% strength aqueous solution of sodium N,N-diethyldithiocarbamate. The phases were separated and the process was repeated once more with 40 ml of the dithiocarbamate solution. The phases were separated, the organic phase was washed with 3×150 ml of water and precipitated by adding it in two times the volume of methanol. The raw polymer was dissolved in chlorobenzene, filtered using celite and precipitated by adding two times the volume of methanol. 1.84 g (64% Th.) of the polymer P2 were obtained, which is soluble in chlorobenzene but insoluble in toluene, THF or chloroform.
  • Example 3 Synthesis of a Cationically Crosslinkable Molecule V1 for use as a Buffer Layer
  • Figure US20070034862A1-20070215-C00010
  • The synthesis of the cationically crosslinkable molecule V1 is described in M. S. Bayer et al., Macromol. Rapid Commun. 1999, 20, 224-228.
  • The device results, which were obtained when using the polymers P1 and P2 or molecule V1 as the buffer layer, are summarized in Examples 6-8.
  • Example 4 Production of LEDs with an Additional Buffer Layer
  • The LEDs were produced according to a general method which was adapted to the respective conditions (for example solution viscosity and optimal layer thickness of the functional layers in the device) in the particular case. The LEDs described below were respectively three-layer systems (three organic layers), i.e. substrate//ITO//PEDOT//buffer layer//polymer//cathode. PEDOT is a polythiophene derivative (Baytron P4083 from H. C. Stark, Goslar). Ba from Aldrich and Ag from Aldrich were used for the cathode in all cases. The way in which PLEDs can generally be produced is described in detail in WO 04/037887 and the literature cited therein.
  • In contrast to this, a cationically crosslinkable semiconductor was applied as a buffer layer on the PEDOT layer. Here, the crosslinkable polymers P1 and P2 or the crosslinkable low molecular weight compound V1 were used as materials for the buffer layer. A solution (with a concentration of 4-25 mg/ml in for example toluene, chlorobenzene, xylene etc.) of the crosslinkable material was taken and dissolved by stirring at room temperature. Depending on the material, it may also be advantageous to stir for some time at 50-70° C. After the complete dissolving of the compound, it was filtered through a 5 μm filter. The buffer layer was then spin coated at variable speeds (400-6000 rpm) with a spin coater in an inert atmosphere. The layer thicknesses could thus be varied in a range of from approximately 20 to 300 nm. The crosslinking was subsequently carried out by heating the device to 180° C. for 30 minutes on a hotplate in an inert atmosphere. The organic semiconductor and the cathode were then applied onto the buffer layer, as described in WO 04/037887 and the literature cited therein.
  • Example 5 Production of Structured LEDs with an Additional Buffer Layer
  • The structured LEDs were produced similarly as Example 4 up to and including the step of crosslinking the buffer layer. In contrast to this, cationically crosslinkable semiconductors were used for the organic semiconductors. These were red, green and blue emitting conjugated polymers based on poly-spirobifluorene, which were functionalized with oxetane groups. These materials and their synthesis are already described in the literature (Nature 2003, 421, 829). A solution (generally with a concentration of 4-25 mg/ml in for example toluene, chlorobenzene, xylene:cyclohexanone (4:1)) was taken and dissolved by stirring at room temperature. Depending on the compound, it may also be advantageous to stir for some time at 50-70° C. Approximately 0.5% by weight (expressed in terms of polymer) of the photoacid {4-[(2-hydroxytetradecyl)-oxyl]-phenyl}-phenyliodonium hexafluoroantimonate was added to the solutions of the cationically crosslinkable semiconductor. The solution of the first cationically crosslinkable semiconductor and the photoacid were then applied onto the crosslinked buffer layer by spin coating under comparable conditions as for the buffer layer. After drying the film, structured crosslinking was carried out by exposure to a UV lamp (10 W, 302 nm, 5 min.) using a mask. The film was then heat-treated in an inert atmosphere for 3 minutes at 130° C., subsequently treated with a 10−4 molar LiAlH4 solution in THF and washed with THF. The non-crosslinked positions in the film were thereby washed off. This process was repeated with the other solutions of the crosslinkable organic semiconductors, and the three primary colors were thereby successively applied in a structured way. The evaporation coating of the electrodes and the contacting were then carried out as described above.
  • Example 6 Lifetime Measurement of an LED with an Additional Buffer Layer P1
  • The LED was produced as described in Example 4. 20 nm of PEDOT were used. A 20 nm thick layer of polymer P1 was applied as the buffer layer, which was thermally crosslinked as described in Example 4. A blue emitting polymer was used as the semiconducting polymer (composition: 50 mol % monomer M7, 30 mol % monomer M8, 10 mol % monomer M1, 10 mol % monomer M9). The monomers are depicted below, and their synthesis is described in WO 03/020790. In electroluminescence, the polymer exhibits a lifetime (=brightness reduction to half the initial brightness) of approximately 1600 h at room temperature and an initial brightness of 300 cd/m2. In a comparative LED without the buffer layer, under otherwise equal conditions, the polymer exhibits a lifetime of approximately 500 h. An LED was also produced whose buffer layer was photochemically crosslinked by adding 0.5% by weight of {4-[(2-hydroxytetradecyl)-oxyl]-phenyl}-phenyliodonium hexafluoroantimonate with exposure to UV radiation (3 s, 302 nm) and subsequent heating to 90° C. for 30 seconds. The buffer layer was then washed with THF and heated to 180° C. for 5 minutes. Under otherwise equal conditions, this LED had a lifetime of approximately 630 h.
    Figure US20070034862A1-20070215-C00011
  • Example 7 Lifetime Measurement of an LED with an Additional Buffer Layer P2
  • The measurement was repeated with polymer P2 as the buffer layer, as described in Example 6 under otherwise identical conditions. The polymer exhibits a lifetime of approximately 1500 h without addition of photoacid to the buffer layer, and approximately 600 h with addition of photoacid.
  • Example 8 Lifetime Measurement of an LED with an Additional Buffer Layer V1
  • The measurement was repeated with compound V1 as the buffer layer, as described in Example 6 under otherwise identical conditions. The polymer exhibits a lifetime of approximately 1350 h without addition of photoacid to the buffer layer, and approximately 550 h with addition of photoacid.

Claims (23)

1. An electronic device containing at least one layer of a conductive doped polymer and at least one layer of an organic semiconductor, characterized in that at least one conducting or semiconducting organic buffer layer which is cationically polymerizable, and to which less than 0.5% of a photoacid is added, is introduced between these layers.
2. The electronic device as claimed in claim 1, characterized in that no photoacid is added to the buffer layer.
3. The electronic device as claimed in claim 1, characterized in that the crosslinking of the organic buffer layer is thermally initiated.
4. The electronic device as claimed in claim 1, wherein the electronic device comprises organic or polymeric light-emitting diodes (OLEDs, PLEDs), organic solar cells (O-SCs), organic field effect transistors (O-FETs), organic circuit elements (O-ICs), organic field quench devices (O-FQDs), organic optical amplifiers or organic laser diodes (O-lasers).
5. The electronic device as claimed in claim 1, wherein the electronic device contains the following elements: substrate, electrode, interlayer of a conductive doped polymer, conducting or semiconducting organic cationically crosslinkable buffer layer, organic semiconductor layer and back electrode.
6. The electronic device as claimed in claim 5, characterized in that an interlayer of a material with a high dielectric constant is introduced between a metal cathode and the organic semiconductor.
7. The electronic device as claimed in claim 1, characterized in that anode materials with a potential of more than 4.5 eV vs. vacuum are used.
8. The electronic device as claimed in claim 1, characterized in that the conductive doped polymer has a conductivity of >10−8 S/cm and a potential of 4-6 eV vs. vacuum.
9. The electronic device as claimed in claim 8, characterized in that derivatives of polythiophene or polyaniline are used as the conductive polymer, and the doping is carried out via polymer-bound Brönsted acids.
10. The electronic device as claimed in claim 5, wherein said organic semiconductor is a low molecular weight oligomeric, dendritic or polymeric semiconducting material.
11. The electronic device as claimed in claim 10, characterized in that the organic semiconductor is a conjugated polymer.
12. The electronic device as claimed in claim 10, characterized in that the organic semiconductor is a cationically crosslinkable compound.
13. The electronic device as claimed in claim 12, characterized in that the cationic crosslinking takes place via ring-opening cationic polymerization of a heterocycle.
14. The electronic device as claimed in claim 13, characterized in that the cationic crosslinking takes place via oxetane groups which can be crosslinked via radiation by adding a photoacid.
15. The electronic device as claimed in claim 1, characterized in that the crosslinkable buffer layer is low molecular weight oligomeric, dendritic or polymeric before the crosslinking.
16. The electronic device as claimed in claim 1, characterized in that the layer thickness of the buffer layer lies in the range of 5-300 nm.
17. The electronic device as claimed in claim 1, characterized in that the potential of the buffer layer lies between the potential of the conductive doped polymer and that of the organic semiconductor.
18. The electronic device as claimed in claim 1, characterized in that cationically crosslinkable hole-conductive materials are used for the buffer layer.
19. The electronic device as claimed in claim 18, characterized in that cationically crosslinkable triarylamine-based, thiophene-based or triarylphosphine-based materials are used for the buffer layer.
20. The electronic device as claimed in claim 1, characterized in that materials in which at least one H atom is replaced by a heterocyclic group, reacting by cationic ring-opening polymerization, are used as materials for the buffer layer.
21. The electronic device as claimed in claim 20, characterized in that the cationically polymerizable heterocycle is a group of the formula (I), (II) or (III),
Figure US20070034862A1-20070215-C00012
in which
R1 in each occurrence is identically or differently hydrogen, a straight-chained, branched or cyclic alkyl, alkoxy or thioalkoxy group having from 1 to 20 C atoms, an aromatic or heteroaromatic ring system having from 4 to 24 aromatic ring atoms or an alkenyl group having from 2 to 10 C atoms, wherein one or more hydrogen atoms may be replaced by halogen or by CN and one or more non-neighboring C atoms may be replaced by —O—, —S—, —CO—, —COO— or —O—CO—; a plurality of R1 radicals may also form a mono- or polycyclic, aliphatic or aromatic ring system with one another or with R2, R3 and/or R4;
R2 in each occurrence is identically or differently hydrogen, a straight-chained, branched or cyclic alkyl group having from 1 to 20 C atoms, an aromatic or heteroaromatic ring system having from 4 to 24 aromatic ring atoms or an alkenyl group having from 2 to 10 C atoms, wherein one or more hydrogen atoms may be replaced by halogen or by CN and one or more non-neighboring C atoms may be replaced by —O—, —S—, —CO—, —COO— or —O—CO—; a plurality of R2 radicals may also form a mono- or polycyclic, aliphatic or aromatic ring system with one another or with R1, R3 and/or R4;
X in each occurrence is identically or differently —O—, —S—, —CO—, —COO—, —O—CO— or a bivalent —(CR3R4)n— group;
Z in each occurrence is identically or differently a bivalent —(CR3R4)n— group;
R3, R4 in each occurrence is identically or differently hydrogen, a straight-chained, branched or cyclic alkyl, alkoxy or thioalkoxy group having from 1 to 20 C atoms, an aromatic or heteroaromatic ring system having from 4 to 24 aromatic ring atoms or an alkenyl group having from 2 to 10 C atoms, wherein one or more hydrogen atoms may be replaced by halogen or by CN; two or more R3 or R4 radicals may also form a ring system with one another or with R1, R2;
n in each occurrence is identically or differently an integer between 0 and 20;
with the proviso that the number of these groups according to formula (I) and/or formula (II) and/or formula (III) is limited by the maximally available, i.e. substitutable H atoms.
22. The electronic device as claimed in claim 21, characterized in that the crosslinking of these units is carried out by thermal treatment of the device.
23. The electronic device as claimed in claim 22, characterized in that the crosslinking takes place at a temperature of from 80 to 200° C. and for a duration of from 0.1 to 120 minutes in an inert atmosphere.
US10/570,640 2003-09-04 2004-09-04 Electronic device comprising an organic semiconductor, an organic semiconductor, and an intermediate buffer layer made of a polymer that is cationically polymerizable and contains no photoacid Abandoned US20070034862A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE2003140711 DE10340711A1 (en) 2003-09-04 2003-09-04 Electronic device containing organic semiconductors
DE10340711.1 2003-09-04
PCT/EP2004/009902 WO2005024970A1 (en) 2003-09-04 2004-09-04 Electronic device comprising an organic semiconductor, an organic semiconductor, and an intermediate buffer layer made of a polymer that is cationically polymerizable and contains no photoacid

Publications (1)

Publication Number Publication Date
US20070034862A1 true US20070034862A1 (en) 2007-02-15

Family

ID=34258390

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/570,372 Expired - Fee Related US7901766B2 (en) 2003-09-04 2004-09-04 Electronic devices comprising an organic conductor and semiconductor as well as an intermediate buffer layer made of a crosslinked polymer
US10/570,640 Abandoned US20070034862A1 (en) 2003-09-04 2004-09-04 Electronic device comprising an organic semiconductor, an organic semiconductor, and an intermediate buffer layer made of a polymer that is cationically polymerizable and contains no photoacid

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10/570,372 Expired - Fee Related US7901766B2 (en) 2003-09-04 2004-09-04 Electronic devices comprising an organic conductor and semiconductor as well as an intermediate buffer layer made of a crosslinked polymer

Country Status (8)

Country Link
US (2) US7901766B2 (en)
EP (2) EP1671379B2 (en)
JP (3) JP5133562B2 (en)
KR (2) KR101042863B1 (en)
CN (2) CN100508237C (en)
AT (2) ATE418161T1 (en)
DE (3) DE10340711A1 (en)
WO (2) WO2005024970A1 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060251886A1 (en) * 2003-09-04 2006-11-09 Mueller David C Electronic devices comprising an organic conductor and semiconductor as well as an intermediate buffer layer made of a crosslinked polymer
US20090026448A1 (en) * 2006-02-13 2009-01-29 Merck Patent Gmbh Electronic component, method for its production and its use
US20090149627A1 (en) * 2006-05-12 2009-06-11 Junyou Pan Indenofluorene polymer based organic semiconductor materials
US20100181556A1 (en) * 2008-11-18 2010-07-22 Ying Wang Organic electronic device with low-reflectance electrode
US20110198575A1 (en) * 2005-12-28 2011-08-18 E. I. Du Pont De Nemours And Company Compositions comprising novel compounds and electronic devices made with such compositions
WO2014046539A1 (en) * 2012-09-18 2014-03-27 Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno Electro-optical device stack
US9502657B2 (en) 2012-09-07 2016-11-22 Pioneer Corporation Organic electroluminescence device and manufacturing method thereof
WO2017065983A1 (en) * 2015-10-16 2017-04-20 Dow Global Technologies Llc Process for making an organic charge transporting film
US9644112B1 (en) * 2016-04-20 2017-05-09 Eastman Kodak Company Articles having electrically-conductive layer or pattern
US10665804B2 (en) * 2017-10-12 2020-05-26 Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. Organic light emitting diode and display device

Families Citing this family (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100738219B1 (en) * 2003-12-23 2007-07-12 삼성에스디아이 주식회사 Substance for Intermediate layer of organic electroluminescent device and organic electroluminescent device using the same
DE102004021567A1 (en) 2004-05-03 2005-12-08 Covion Organic Semiconductors Gmbh Electronic devices containing organic semiconductors
GB2425654B (en) * 2005-04-29 2010-03-17 Seiko Epson Corp A method of fabricating a heterojunction of organic semiconducting polymers
KR100715548B1 (en) * 2005-07-29 2007-05-07 광 석 서 Conducting Polymer Synthesized with Partially Substituted Polymers as a Dopant
US7576356B2 (en) * 2005-08-08 2009-08-18 Osram Opto Semiconductors Gmbh Solution processed crosslinkable hole injection and hole transport polymers for OLEDs
US8440324B2 (en) * 2005-12-27 2013-05-14 E I Du Pont De Nemours And Company Compositions comprising novel copolymers and electronic devices made with such compositions
US8138075B1 (en) 2006-02-06 2012-03-20 Eberlein Dietmar C Systems and methods for the manufacture of flat panel devices
JP4175397B2 (en) * 2006-06-28 2008-11-05 セイコーエプソン株式会社 Method for manufacturing organic electroluminescent device
US8632892B2 (en) 2006-07-19 2014-01-21 Hitachi Chemical Co., Ltd. Organic electronic material, organic electronic device, and organic electroluminescent device
TWI474759B (en) * 2007-02-15 2015-02-21 Mitsubishi Chem Corp Method for manufacturing organic field emitting element and organic field emitting element
JP5196928B2 (en) 2007-09-18 2013-05-15 キヤノン株式会社 Organic light emitting device and display device
KR101532458B1 (en) 2007-11-21 2015-06-29 메르크 파텐트 게엠베하 Conjugated copolymer
US20090236979A1 (en) * 2008-03-24 2009-09-24 Air Products And Chemicals, Inc. Organic Electroluminescent Device and the Method of Making
JP5540600B2 (en) * 2008-08-13 2014-07-02 三菱化学株式会社 Electronic device, organic electroluminescent element, organic EL display device, and organic EL lighting
JP5359255B2 (en) * 2008-12-19 2013-12-04 コニカミノルタ株式会社 Organic photoelectric conversion element
JP5141600B2 (en) * 2009-03-09 2013-02-13 三菱化学株式会社 Method for producing composition for organic electroluminescent device
CN101624589B (en) * 2009-04-10 2011-08-31 重庆大学 Novel Rhizopus oryzae immobilized fermentation carrier unit and use method
KR101335155B1 (en) * 2009-06-01 2013-12-02 히타치가세이가부시끼가이샤 Organic electronic material, ink composition containing same, and organic thin film, organic electronic element, organic electroluminescent element, lighting device, and display device formed therewith
US8575303B2 (en) * 2010-01-19 2013-11-05 Sirigen Group Limited Reagents for directed biomarker signal amplification
US8859171B2 (en) * 2010-03-03 2014-10-14 Xerox Corporation Charge transport particles
KR101181228B1 (en) * 2010-10-11 2012-09-10 포항공과대학교 산학협력단 Organic solar cell and method for preparing the same
KR101756657B1 (en) * 2010-11-03 2017-07-12 엘지디스플레이 주식회사 White organic light emitting device and display device using the same
JP5944120B2 (en) * 2011-07-21 2016-07-05 コニカミノルタ株式会社 ORGANIC PHOTOELECTRIC CONVERSION DEVICE, ITS MANUFACTURING METHOD, AND ORGANIC SOLAR CELL USING THE SAME
KR20150052024A (en) * 2012-09-04 2015-05-13 미쯔비시 가가꾸 가부시끼가이샤 Organic electroluminescent device and manufacturing method thereof
WO2014048542A1 (en) * 2012-09-27 2014-04-03 Merck Patent Gmbh Materials for organic electroluminescent devices
JP6371304B2 (en) * 2012-12-13 2018-08-08 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニーE.I.Du Pont De Nemours And Company Confinement layer and methods and materials for manufacturing devices manufactured using the same
KR102372211B1 (en) * 2014-03-27 2022-03-08 닛산 가가쿠 가부시키가이샤 Charge-transporting varnish
EP3131131B1 (en) * 2014-04-09 2021-08-25 Sumitomo Chemical Company Limited Light-emission element, and composition used therein
CN107406588B (en) * 2015-02-25 2020-06-23 三菱化学株式会社 Polymer, composition for organic electroluminescent element, organic EL display device, and organic EL lighting
CN110036498B (en) 2016-12-06 2023-04-18 默克专利有限公司 Method for manufacturing electronic device
CN109563243B (en) * 2017-03-24 2022-07-08 日产化学株式会社 Fluorine atom-containing polymer and use thereof
JP2018203889A (en) 2017-06-06 2018-12-27 日立化成株式会社 Curable polymer, polymerization liquid, conductive film and organic light-emitting element
EP3651223A4 (en) * 2017-07-04 2021-03-17 Hitachi Chemical Company, Ltd. Organic electronics material and organic electronics element
KR102385225B1 (en) 2017-07-12 2022-04-11 삼성디스플레이 주식회사 Composition for fabricating organic film, display device using the same and method for manufacturing the display device
WO2020011701A1 (en) * 2018-07-11 2020-01-16 Merck Patent Gmbh Formulation containing a highly branched polymer, highly branched polymer and electro-optical device containing this highly branched polymer
KR20200069400A (en) 2018-12-05 2020-06-17 삼성디스플레이 주식회사 Condensed ring compound, composition including the same and organic light-emitting device including thin film formed therefrom
KR20220036393A (en) 2020-09-14 2022-03-23 삼성디스플레이 주식회사 Display device
KR20220060630A (en) 2020-11-04 2022-05-12 삼성디스플레이 주식회사 Conductive bonding structure for boards and display device including the same

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5518824A (en) * 1993-08-02 1996-05-21 Basf Aktiengesellschaft Electroluminescent arrangement
US5792557A (en) * 1994-02-08 1998-08-11 Tdk Corporation Organic EL element
US20030180574A1 (en) * 2002-02-22 2003-09-25 Wen-Yao Huang Efficient organic electroluminescent devices with red fluorescent dopants
US20040028804A1 (en) * 2002-08-07 2004-02-12 Anderson Daniel G. Production of polymeric microarrays
US20040054152A1 (en) * 2000-08-01 2004-03-18 Klaus Meerholz Materials that can be structured, method for producing the same and their use
US20050017629A1 (en) * 2003-07-22 2005-01-27 Altair Center, Llc. Light emitting devices based on hyperbranched polymers with lanthanide ions
US20060251886A1 (en) * 2003-09-04 2006-11-09 Mueller David C Electronic devices comprising an organic conductor and semiconductor as well as an intermediate buffer layer made of a crosslinked polymer

Family Cites Families (45)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4720432A (en) 1987-02-11 1988-01-19 Eastman Kodak Company Electroluminescent device with organic luminescent medium
US5331183A (en) 1992-08-17 1994-07-19 The Regents Of The University Of California Conjugated polymer - acceptor heterojunctions; diodes, photodiodes, and photovoltaic cells
JP3082479B2 (en) * 1992-10-23 2000-08-28 ジェイエスアール株式会社 Negative radiation-sensitive resin composition
JP2848207B2 (en) 1993-09-17 1999-01-20 凸版印刷株式会社 Organic thin film EL device
DE59510315D1 (en) 1994-04-07 2002-09-19 Covion Organic Semiconductors Spiro compounds and their use as electroluminescent materials
JP4392057B2 (en) 1994-05-16 2009-12-24 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Semiconductor device having organic semiconductor material
JP3246189B2 (en) 1994-06-28 2002-01-15 株式会社日立製作所 Semiconductor display device
TW293172B (en) 1994-12-09 1996-12-11 At & T Corp
DE19500912A1 (en) * 1995-01-13 1996-07-18 Basf Ag Electroluminescent arrangement
EP0842208B2 (en) * 1995-07-28 2009-08-19 Sumitomo Chemical Company, Limited 2,7-aryl-9-substituted fluorenes and 9-substituted fluorene oligomers and polymers
KR100431015B1 (en) * 1995-07-28 2004-07-30 다우 글로벌 테크놀로지스 인크. 2,7-aryl-9-substituted fluorenes and 9-substituted fluorene oligomers and polymers
US5929194A (en) * 1996-02-23 1999-07-27 The Dow Chemical Company Crosslinkable or chain extendable polyarylpolyamines and films thereof
JP3643433B2 (en) 1996-03-25 2005-04-27 ケミプロ化成株式会社 Triphenylamine-containing polyetherketone, process for producing the same, and organic EL device using the same
WO1998003566A1 (en) 1996-07-19 1998-01-29 The Regents Of The University Of California Conjugated polymers as materials for solid state lasers
JP3899566B2 (en) 1996-11-25 2007-03-28 セイコーエプソン株式会社 Manufacturing method of organic EL display device
DE19652261A1 (en) 1996-12-16 1998-06-18 Hoechst Ag Aryl-substituted poly (p-arylenevinylenes), process for their preparation and their use in electroluminescent devices
DE19711713A1 (en) 1997-03-20 1998-10-01 Hoechst Ag Photovoltaic cell
US6309763B1 (en) * 1997-05-21 2001-10-30 The Dow Chemical Company Fluorene-containing polymers and electroluminescent devices therefrom
JP4509228B2 (en) 1997-08-22 2010-07-21 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Field effect transistor made of organic material and method of manufacturing the same
JP2000077185A (en) 1998-08-28 2000-03-14 Asahi Chem Ind Co Ltd Organic electroluminescent element
US6107452A (en) 1998-10-09 2000-08-22 International Business Machines Corporation Thermally and/or photochemically crosslinked electroactive polymers in the manufacture of opto-electronic devices
KR100400291B1 (en) * 1998-11-27 2004-02-05 주식회사 하이닉스반도체 Novel photoresist monomer, polymer thereof and photoresist composition using the same
EP1151484A1 (en) 1999-01-15 2001-11-07 The Dow Chemical Company Semiconducting polymer field effect transistor
JP2001076874A (en) * 1999-09-07 2001-03-23 Tdk Corp Organic el display device
KR20020095210A (en) * 2000-04-11 2002-12-20 듀폰 디스플레이즈, 인크. Soluble Poly(aryl-oxadiazole) Conjugated Polymers
DE10044840A1 (en) * 2000-09-11 2002-04-04 Siemens Ag Photostructurable new organic semiconductor materials
JP4307839B2 (en) 2001-03-10 2009-08-05 メルク パテント ゲーエムベーハー Organic semiconductor solutions and dispersions
JP2003007471A (en) * 2001-04-13 2003-01-10 Semiconductor Energy Lab Co Ltd Organic light emitting element and luminescence equipment using the element
EP1390962B2 (en) * 2001-05-16 2023-07-05 The Trustees Of Princeton University High efficiency multi-color electro-phosphorescent oleds
JP2003007475A (en) * 2001-06-20 2003-01-10 Honda Motor Co Ltd Organic electroluminescence element
JP2003029400A (en) * 2001-07-19 2003-01-29 Fuji Photo Film Co Ltd Image forming material
DE10143353A1 (en) 2001-09-04 2003-03-20 Covion Organic Semiconductors Conjugated polymers containing spirobifluorene units and their use
JP2003103696A (en) * 2001-09-27 2003-04-09 Hitachi Chem Co Ltd Plate for forming irregularity, its manufacturing method, electromagnetic wave shielding material using the same, its manufacturing method, and electromagnetic wave shielding component and electromagnetic wave shield display which use the electromagnetic wave shielding component
EP1308781A3 (en) 2001-10-05 2003-09-03 Shipley Co. L.L.C. Cyclic sulfonium and sulfoxonium photoacid generators and photoresists containing them
JP2003142272A (en) * 2001-11-01 2003-05-16 Nichia Chem Ind Ltd Polymeric hole transport material, and organic electroluminescent element using the same
JP4197117B2 (en) 2001-11-22 2008-12-17 シャープ株式会社 Organic thin film device using polymer material having carrier transport property, method for manufacturing organic thin film device, and wiring
JP2003163086A (en) * 2001-11-27 2003-06-06 Nippon Hoso Kyokai <Nhk> Organic el cell and organic el display
US6743757B2 (en) * 2001-12-06 2004-06-01 Infineum International Ltd. Dispersants and lubricating oil compositions containing same
DE10159946A1 (en) 2001-12-06 2003-06-18 Covion Organic Semiconductors Process for the production of aryl-aryl coupled compounds
JP3946671B2 (en) 2002-07-23 2007-07-18 三星エスディアイ株式会社 Image display device based on photon emission suppression element and image display method using the same
US7531377B2 (en) 2002-09-03 2009-05-12 Cambridge Display Technology Limited Optical device
DE10249723A1 (en) 2002-10-25 2004-05-06 Covion Organic Semiconductors Gmbh Conjugated polymers containing arylamine units, their preparation and use
GB0226010D0 (en) * 2002-11-08 2002-12-18 Cambridge Display Tech Ltd Polymers for use in organic electroluminescent devices
US6982179B2 (en) * 2002-11-15 2006-01-03 University Display Corporation Structure and method of fabricating organic devices
KR101172526B1 (en) 2003-05-12 2012-08-13 캠브리지 엔터프라이즈 리미티드 Manufacture of a polymer device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5518824A (en) * 1993-08-02 1996-05-21 Basf Aktiengesellschaft Electroluminescent arrangement
US5792557A (en) * 1994-02-08 1998-08-11 Tdk Corporation Organic EL element
US20040054152A1 (en) * 2000-08-01 2004-03-18 Klaus Meerholz Materials that can be structured, method for producing the same and their use
US20030180574A1 (en) * 2002-02-22 2003-09-25 Wen-Yao Huang Efficient organic electroluminescent devices with red fluorescent dopants
US20040028804A1 (en) * 2002-08-07 2004-02-12 Anderson Daniel G. Production of polymeric microarrays
US20050017629A1 (en) * 2003-07-22 2005-01-27 Altair Center, Llc. Light emitting devices based on hyperbranched polymers with lanthanide ions
US20060251886A1 (en) * 2003-09-04 2006-11-09 Mueller David C Electronic devices comprising an organic conductor and semiconductor as well as an intermediate buffer layer made of a crosslinked polymer

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060251886A1 (en) * 2003-09-04 2006-11-09 Mueller David C Electronic devices comprising an organic conductor and semiconductor as well as an intermediate buffer layer made of a crosslinked polymer
US7901766B2 (en) 2003-09-04 2011-03-08 Merck Patent Gmbh Electronic devices comprising an organic conductor and semiconductor as well as an intermediate buffer layer made of a crosslinked polymer
US20110198575A1 (en) * 2005-12-28 2011-08-18 E. I. Du Pont De Nemours And Company Compositions comprising novel compounds and electronic devices made with such compositions
US20090026448A1 (en) * 2006-02-13 2009-01-29 Merck Patent Gmbh Electronic component, method for its production and its use
US20110065222A1 (en) * 2006-02-13 2011-03-17 Merck Patent Gmbh Electronic component, method for its production and its use
US8278394B2 (en) 2006-05-12 2012-10-02 MERCK Patent Gesellschaft mit beschränkter Haftung Indenofluorene polymer based organic semiconductor materials
US20090149627A1 (en) * 2006-05-12 2009-06-11 Junyou Pan Indenofluorene polymer based organic semiconductor materials
US8643000B2 (en) * 2008-11-18 2014-02-04 E I Du Pont De Nemours And Company Organic electronic device with low-reflectance electrode
US20100181556A1 (en) * 2008-11-18 2010-07-22 Ying Wang Organic electronic device with low-reflectance electrode
US9502657B2 (en) 2012-09-07 2016-11-22 Pioneer Corporation Organic electroluminescence device and manufacturing method thereof
US9882176B2 (en) 2012-09-07 2018-01-30 Pioneer Corporation Organic electroluminescence device and manufacturing method thereof
US10135036B2 (en) 2012-09-07 2018-11-20 Pioneer Corporation Organic electroluminescence device and manufacturing method thereof
WO2014046539A1 (en) * 2012-09-18 2014-03-27 Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno Electro-optical device stack
US9478765B2 (en) 2012-09-18 2016-10-25 Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno Electro-optical device stack, having patches covering layer breaches
WO2017065983A1 (en) * 2015-10-16 2017-04-20 Dow Global Technologies Llc Process for making an organic charge transporting film
US20180358558A1 (en) * 2015-10-16 2018-12-13 Dow Global Technologies Llc Process for making an organic charge transporting film
US10868253B2 (en) * 2015-10-16 2020-12-15 Rohm And Haas Electronic Materials Llc Process for making an organic charge transporting film
US9644112B1 (en) * 2016-04-20 2017-05-09 Eastman Kodak Company Articles having electrically-conductive layer or pattern
US10665804B2 (en) * 2017-10-12 2020-05-26 Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd. Organic light emitting diode and display device

Also Published As

Publication number Publication date
DE502004012028D1 (en) 2011-02-03
KR101071034B1 (en) 2011-10-06
JP5355857B2 (en) 2013-11-27
WO2005024970A1 (en) 2005-03-17
EP1671379B1 (en) 2010-12-22
JP2013191867A (en) 2013-09-26
JP5133562B2 (en) 2013-01-30
JP2007504657A (en) 2007-03-01
EP1661191B1 (en) 2008-12-17
KR20060096414A (en) 2006-09-11
US20060251886A1 (en) 2006-11-09
ATE492913T1 (en) 2011-01-15
ATE418161T1 (en) 2009-01-15
CN1849717A (en) 2006-10-18
EP1671379B8 (en) 2011-03-23
WO2005024971A1 (en) 2005-03-17
KR101042863B1 (en) 2011-06-20
US7901766B2 (en) 2011-03-08
EP1671379A1 (en) 2006-06-21
DE502004008698D1 (en) 2009-01-29
DE10340711A1 (en) 2005-04-07
CN1864280A (en) 2006-11-15
EP1661191A1 (en) 2006-05-31
EP1671379B2 (en) 2014-10-01
KR20070036014A (en) 2007-04-02
JP2007504656A (en) 2007-03-01
CN100508237C (en) 2009-07-01

Similar Documents

Publication Publication Date Title
US20070034862A1 (en) Electronic device comprising an organic semiconductor, an organic semiconductor, and an intermediate buffer layer made of a polymer that is cationically polymerizable and contains no photoacid
JP5096378B2 (en) Organic electronic device, manufacturing method thereof and use thereof
KR101139739B1 (en) Method for cross-linking an organic semi-conductor
Yang et al. Deep-red electroluminescent polymers: synthesis and characterization of new low-band-gap conjugated copolymers for light-emitting diodes and photovoltaic devices
US7323533B2 (en) Conjugated polymers containing spirobifluorene units and the use thereof
JP5704729B2 (en) Hard amine
WO2005034199A2 (en) Organic diodes and materials
JP5798108B2 (en) Organic electroluminescence device and manufacturing method
JP5746226B2 (en) Cyclopentadienedithiophene-quinoxaline copolymer, production method thereof, and application thereof
KR101829091B1 (en) Materials for optoelectronic devices
KR20050059166A (en) Optical device
JP2008525608A5 (en)
JP2011018922A (en) Optical device
US20180309065A1 (en) Charge transfer salt, electronic device and method of forming the same
KR101637058B1 (en) Nitrogen-containg compound and organic solar cell comprising the same
Dumur et al. Photoinitiated Cross‐Linking in OLEDs: An Efficient Tool for Addressing the Solution‐Processed Devices Elaboration and Stability Issues
JP2010251235A (en) Electronic element

Legal Events

Date Code Title Description
AS Assignment

Owner name: MERCK OLED MATERIALS GMBH,GERMANY

Free format text: CHANGE OF NAME;ASSIGNOR:COVION ORGANIC SEMICONDUCTORS GMBH;REEL/FRAME:018097/0118

Effective date: 20050727

Owner name: MERCK OLED MATERIALS GMBH, GERMANY

Free format text: CHANGE OF NAME;ASSIGNOR:COVION ORGANIC SEMICONDUCTORS GMBH;REEL/FRAME:018097/0118

Effective date: 20050727

AS Assignment

Owner name: MERCK PATENT GMBH,GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MERCK OLED MATERIALS GMBH;REEL/FRAME:018821/0477

Effective date: 20061114

Owner name: MERCK PATENT GMBH, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MERCK OLED MATERIALS GMBH;REEL/FRAME:018821/0477

Effective date: 20061114

AS Assignment

Owner name: COVION ORGANIC SEMICONDUCTORS GMBH, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:PARHAM, AMIR;FALCOU, AURELIE;HEUN, SUSANNE;AND OTHERS;REEL/FRAME:019037/0630;SIGNING DATES FROM 20061108 TO 20070205

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION