WO2010048547A2 - Photovoltaic device with increased light trapping - Google Patents
Photovoltaic device with increased light trapping Download PDFInfo
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- WO2010048547A2 WO2010048547A2 PCT/US2009/061911 US2009061911W WO2010048547A2 WO 2010048547 A2 WO2010048547 A2 WO 2010048547A2 US 2009061911 W US2009061911 W US 2009061911W WO 2010048547 A2 WO2010048547 A2 WO 2010048547A2
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- 239000006117 anti-reflective coating Substances 0.000 claims abstract description 14
- 239000002245 particle Substances 0.000 claims description 17
- 239000004065 semiconductor Substances 0.000 claims description 16
- 239000002923 metal particle Substances 0.000 claims description 11
- 229910001218 Gallium arsenide Inorganic materials 0.000 claims description 5
- 239000003973 paint Substances 0.000 claims description 5
- 239000004793 Polystyrene Substances 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 229920002223 polystyrene Polymers 0.000 claims description 4
- 239000011521 glass Substances 0.000 claims description 2
- 229910001635 magnesium fluoride Inorganic materials 0.000 claims 1
- 239000006096 absorbing agent Substances 0.000 abstract description 16
- 238000000034 method Methods 0.000 abstract description 13
- 238000007788 roughening Methods 0.000 abstract description 5
- 230000005670 electromagnetic radiation Effects 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 132
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- 239000011248 coating agent Substances 0.000 description 7
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- 229910052581 Si3N4 Inorganic materials 0.000 description 5
- FTWRSWRBSVXQPI-UHFFFAOYSA-N alumanylidynearsane;gallanylidynearsane Chemical compound [As]#[Al].[As]#[Ga] FTWRSWRBSVXQPI-UHFFFAOYSA-N 0.000 description 5
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 5
- 239000005083 Zinc sulfide Substances 0.000 description 4
- 229910052984 zinc sulfide Inorganic materials 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 238000001312 dry etching Methods 0.000 description 2
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000002161 passivation Methods 0.000 description 2
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 2
- 238000001039 wet etching Methods 0.000 description 2
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 2
- 229910003070 TaOx Inorganic materials 0.000 description 1
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- 238000002488 metal-organic chemical vapour deposition Methods 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
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- 229910052710 silicon Inorganic materials 0.000 description 1
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- 238000004544 sputter deposition Methods 0.000 description 1
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- 239000004408 titanium dioxide Substances 0.000 description 1
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier
- H01L31/072—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type
- H01L31/0735—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type comprising only AIIIBV compound semiconductors, e.g. GaAs/AlGaAs or InP/GaInAs solar cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/0216—Coatings
- H01L31/02161—Coatings for devices characterised by at least one potential jump barrier or surface barrier
- H01L31/02167—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells
- H01L31/02168—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells the coatings being antireflective or having enhancing optical properties for the solar cells
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/544—Solar cells from Group III-V materials
Definitions
- Embodiments of the present invention generally relate to photovoltaic (PV) devices, such as solar cells, with increased efficiency and greater flexibility and methods for fabricating the same.
- PV photovoltaic
- the junction of a solar cell absorbs photons to produce electron-hole pairs, which are separated by the internal electric field of the junction to generate a voltage, thereby converting light energy to electric energy.
- the generated voltage can be increased by connecting solar cells in series, and the current may be increased by connecting solar cells in parallel.
- Solar cells may be grouped together on solar panels.
- An inverter may be coupled to several solar panels to convert DC power to AC power.
- Embodiments of the present invention generally relate to methods and apparatus for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells.
- PV device generally includes a p + -doped layer, an n-doped layer disposed above the p + -doped layer to form a p-n layer such that electric energy is created when photons are absorbed by the p-n layer, a window layer disposed above the n-doped layer, and an antireflective coating disposed above the window layer.
- the PV device generally includes a p + -doped layer, an n-doped layer disposed above the p + -doped layer to form a p-n layer such that electric energy is created when light is absorbed by the p-n layer, a window layer disposed above the n-doped layer, and a diffuser disposed below the p + -doped layer.
- FIG. 1 illustrates multiple epitaxial layers for a photovoltaic (PV) unit in cross-section, in accordance with an embodiment of the present invention.
- FIG. 2 illustrates an antireflective coating added to the semiconductor layers on the front side of the PV unit, in accordance with an embodiment of the present invention.
- FIG. 3 illustrates roughening a window layer before applying the antireflective coating, in accordance with an embodiment of the present invention.
- FIG. 4 illustrates multiple window layers, wherein the outermost window layer is roughened before the antireflective coating is applied, in accordance with an embodiment of the present invention.
- FIG. 5 illustrates a roughened emitter layer on the back side of the PV unit, in accordance with an embodiment of the present invention.
- FIG. 6 illustrates a diffuser on the back side of the PV unit, in accordance with an embodiment of the present invention.
- FIG. 7 illustrates dielectric particles and white paint functioning as the diffuser of FIG. 6, in accordance with an embodiment of the present invention.
- FIG. 8 illustrates metal particles functioning as the diffuser of FIG. 6, in accordance with an embodiment of the present invention.
- Embodiments of the present invention provide techniques and apparatus for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells.
- FIG. 1 illustrates various epitaxial layers of a photovoltaic (PV) unit 100 in cross-section.
- the various layers may be formed using any suitable method for semiconductor growth, such as molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD) 1 on a substrate (not shown).
- MBE molecular beam epitaxy
- MOCVD metalorganic chemical vapor deposition
- the PV unit 100 may comprise a window layer 106 formed above the substrate and any underlying buffer layer(s).
- the window layer 106 may comprise aluminum gallium arsenide (AIGaAs), such as Alo .3 Gao .7 As.
- AIGaAs aluminum gallium arsenide
- the window layer 106 may be undoped.
- the window layer 106 may be transparent to allow photons to pass through the window layer on the front side of the PV unit to other underlying layers.
- a base layer 108 may be formed above the window layer 106.
- the base layer 108 may comprise any suitable group MI-V compound semiconductor, such as GaAs.
- the base layer 108 may be monocrystalline and may be n-doped.
- an emitter layer 110 may be formed above the base layer 108.
- the emitter layer 110 may comprise any suitable group MI-V compound semiconductor for forming a heterojunction with the base layer 108.
- the emitter layer 110 may comprise a different semiconductor material, such as AIGaAs (e.g., Alo .3 Gao .7 As).
- AIGaAs e.g., Alo .3 Gao .7 As
- the emitter layer 110 and the window layer 106 both comprise AIGaAs
- the Al x Ga-i -x As composition of the emitter layer 110 may be the same as or different than the Al y Ga- ⁇ -y As composition of the window layer.
- the emitter layer 110 may be monocrystalline and may be heavily p-doped (i.e., p + -doped).
- the combination of the base layer 108 and the emitter layer 110 may form an absorber layer for absorbing photons.
- conventional photovoltaic semiconductor devices typically have a p-doped base layer and an n + -doped emitter layer.
- the base layer is typically p- doped in conventional devices due to the diffusion length of the carriers.
- cavities or recesses 114 may be formed in the emitter layer deep enough to reach the underlying base layer 108.
- Such recesses 114 may be formed by applying a mask to the emitter layer 110 using photolithography, for example, and removing the semiconductor material in the emitter layer 110 not covered by the mask using any suitable technique, such as wet or dry etching. In this manner, the base layer 108 may be accessed via the back side of the PV unit iOO.
- an interface layer 116 may be formed above the emitter layer 110.
- the interface layer 116 may comprise any suitable group Hl-V compound semiconductor, such as GaAs.
- the interface layer 116 may be p + -doped.
- the functional layers of the PV unit 100 may be separated from the buffer layer(s) 102 and substrate during an epitaxial lift-off (ELO) process.
- ELO epitaxial lift-off
- the absorber layer of an ideal photovoltaic (PV) device would absorb all of the photons impinging on the PV device's front side facing the light source since the open circuit voltage (V oc ) or short circuit current (/ JC ) is proportional to the light intensity.
- V oc open circuit voltage
- / JC short circuit current
- several loss mechanisms typically interfere with the PV device's absorber layer seeing or absorbing all of the light reaching the front side of the device.
- the semiconductor layers of the PV device may be shiny (especially when made of pure silicon) and, therefore, may reflect a substantial portion of the impinging photons, preventing these photons from ever reaching the absorber layer.
- the absorber layer may not absorb all of the impinging photons; some photons may pass through the absorber layer without affecting any electron-hole pairs.
- Apparatus for trapping the light within the semiconductor layers of a PV device may be divided into two categories: front side light trapping and back side light trapping.
- front side light trapping By employing both types of light trapping in a PV device, the idea is that nearly all photons impinging on the PV device's front side may be captured and "bounce around" within the semiconductor layers until the photons are absorbed by the absorber layer and converted to electric energy.
- FIG. 2 illustrates an antireflective (AR) coating 802 disposed adjacent to the window layer 106 on the front side of the PV unit 100, in accordance with an embodiment of the present invention.
- the AR coating 802 may comprise any suitable material that allows light to pass through while preventing light reflection from its surface.
- the AR coating 802 may comprise magnesium fluoride (MgF 2 ), zinc sulfide (ZnS), silicon nitride (SiN), titanium dioxide (Ti ⁇ 2), silicon dioxide (Si ⁇ 2), or any combination thereof.
- the AR coating 802 may be applied to the window layer 106 by any suitable technique, such as sputtering.
- the window layer 106 may be roughened or textured before applying the antireflective coating 802.
- FIG. 3 illustrates a roughened window layer 106.
- Roughening of the window layer 106 may be accomplished by wet etching or dry etching, for example. Texturing may be achieved by applying small particles, such as polystyrene spheres, to the surface of the window layer 106 before applying the AR coating 802. By roughening or texturing the window layer 106, different angles are provided at the interface between the AR coating 802 and the window layer, which may have different indices of refraction.
- the window layer 106 may provide increased light trapping.
- the window layer 106 may comprise multiple window layers.
- the outermost window layer i.e., the window layer closest to the front side of the PV unit 100
- the window layer 106 may be roughened or textured as described above before the antireflective coating 802 is applied, as illustrated in FIG. 4.
- the window layer 106 comprises a first window layer 1002 disposed adjacent to the base layer 108 and a second window layer 1004 interposed between the first window layer 1002 and the antireflective coating 802.
- the first and second window layers 1002, 1004 may comprise any material suitable for the window layer 106 as described above, such as AIGaAs, but typically with different compositions.
- the first window layer 1002 may comprise Alo.
- the second window layer 1004 may comprise Alo .1 Gao .9 As. Furthermore, some of the multiple window layers may be doped, while others are undoped for some embodiments. For example, the first window layer 1002 may be doped, and the second window layer 1004 may be undoped. EXEMPLARY BACK SIDE LIGHT TRAPPING
- the emitter layer 110 on the back side of the PV unit 100 may be roughened or textured, as described above with respect to the front side, in an effort to increase light trapping.
- FIG. 5 illustrates such a roughened emitter layer 110.
- FIG. 6 illustrates a diffuser 1202 on the back side of the PV unit 100 in an effort to increase the amount of light captured by the absorber layer.
- the purpose of the diffuser 1202 is to diffuse or scatter photons that pass through the absorber layer without being absorbed.
- the diffuser 1202 may be covered with a reflective layer 1204. In this manner, the diffuser 1202 may provide new angles to incident photons, some of which may be redirected back to the interior of the PV unit.
- the reflective layer 1204 may redirect these photons back through the diffuser 1202 and towards the interior of the PV unit. Although some of the light may be absorbed by the diffuser 1202 as the photons are scattered and redirected inside, much of the light is redirected to the absorber layer to be absorbed and converted into electric energy, thereby increasing efficiency. Conventional PV devices without a diffuser and a reflective layer may not be able to recapture photons that reach the back side of the device without being absorbed initially by the absorber layer.
- the diffuser 1202 may comprise dielectric particles 1302, as illustrated in FIG. 7.
- the dielectric particles may comprise any suitable material which is electrically insulative and does not absorb light.
- the dielectric particles 1302 may have a diameter in range from about 0.2 to 2.0 ⁇ m.
- the dielectric particles 1302 may be covered by white paint 1304, which reflects light and may act as the reflective layer for redirecting photons back to the interior of the PV unit 100.
- the white paint 1304 may comprise T ⁇ O 2 , for example.
- the diffuser 1202 may comprise metal particles 1402, as illustrated in FIG. 8.
- the metal particles 1402 may reflect photons that were not absorbed by the absorber layer, and by having a multitude of metal particles 1402, the photons may be scattered in different directions several times before being redirected to the interior of the PV unit 100.
- the metal particles 1402 may have a diameter of about 150 to 200 nm, functioning as relatively compact scatterers. With thinner particles in the diffuser 1202, the thickness of the PV unit 100 may be kept smaller, thereby maintaining the desired flexibility of the PV unit 100.
- the metal particles 1402 are electrically conductive, lateral surfaces of the interface layer 116 may be passivated to prevent the metal particles 1402 from interfering with the operation of the device.
- the interface layer 116 may be passivated using any suitable passivation method, such as chemical vapor deposition (CVD) or plasma-enhanced CVD (PECVD).
- the passivation 1404 may comprise any suitable electrically non-conductive material, such as silicon nitride (SiN), SiO x , TiO x , TaO x , zinc sulfide (ZnS), or any combination thereof.
- a dielectric layer 1406 may be formed above the metal particles 1402 in an effort to avoid shunting any back side contacts, as depicted in FIG. 8.
- the dielectric layer 1406 may comprise any suitable electrically insulative material, such as Si ⁇ 2, SiN, or glass.
Abstract
Methods and apparatus are provided for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells. A photovoltaic (PV) device may incorporate front side and/or back side light trapping techniques in an effort to absorb as many of the photons incident on the front side of the PV device as possible in the absorber layer. The light trapping techniques may include a front side antireflective coating, multiple window layers, roughening or texturing on the front and/or the back sides, a back side diffuser for scattering the light, and/or a back side reflector for redirecting the light into the interior of the PV device. With such light trapping techniques, more light may be absorbed by the absorber layer for a given amount of incident light, thereby increasing the efficiency of the PV device.
Description
PHOTOVOLTAIC DEVICE WITH INCREASED LIGHT TRAPPING
BACKGROUND
Technical Field
[0001] Embodiments of the present invention generally relate to photovoltaic (PV) devices, such as solar cells, with increased efficiency and greater flexibility and methods for fabricating the same.
Description of the Related Art
[0002] As fossil fuels are being depleted at ever-increasing rates, the need for alternative energy sources is becoming more and more apparent. Energy derived from wind, from the sun, and from flowing water offer renewable, environment- friendly alternatives to fossil fuels, such as coal, oil, and natural gas. Being readily available almost anywhere on Earth, solar energy may someday be a viable alternative.
[0003] To harness energy from the sun, the junction of a solar cell absorbs photons to produce electron-hole pairs, which are separated by the internal electric field of the junction to generate a voltage, thereby converting light energy to electric energy. The generated voltage can be increased by connecting solar cells in series, and the current may be increased by connecting solar cells in parallel. Solar cells may be grouped together on solar panels. An inverter may be coupled to several solar panels to convert DC power to AC power.
[0004] Nevertheless, the currently high cost of producing solar cells relative to the low efficiency levels of contemporary devices is preventing solar cells from becoming a mainstream energy source and limiting the applications to which solar cells may be suited. Accordingly, there is a need for more efficient photovoltaic devices suitable for a myriad of applications.
SUMMARY OF THE INVENTION
[0005] Embodiments of the present invention generally relate to methods and apparatus for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells.
[0006] One embodiment of the present invention provides a photovoltaic (PV) device. The PV device generally includes a p+-doped layer, an n-doped layer disposed above the p+-doped layer to form a p-n layer such that electric energy is created when photons are absorbed by the p-n layer, a window layer disposed above the n-doped layer, and an antireflective coating disposed above the window layer.
[0007] Another embodiment of the present invention provides a PV device. The PV device generally includes a p+-doped layer, an n-doped layer disposed above the p+-doped layer to form a p-n layer such that electric energy is created when light is absorbed by the p-n layer, a window layer disposed above the n-doped layer, and a diffuser disposed below the p+-doped layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the above-recited features of the invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0009] FIG. 1 illustrates multiple epitaxial layers for a photovoltaic (PV) unit in cross-section, in accordance with an embodiment of the present invention.
[0010] FIG. 2 illustrates an antireflective coating added to the semiconductor layers on the front side of the PV unit, in accordance with an embodiment of the present invention.
[0011] FIG. 3 illustrates roughening a window layer before applying the antireflective coating, in accordance with an embodiment of the present invention.
[0012] FIG. 4 illustrates multiple window layers, wherein the outermost window layer is roughened before the antireflective coating is applied, in accordance with an embodiment of the present invention.
[0013] FIG. 5 illustrates a roughened emitter layer on the back side of the PV unit, in accordance with an embodiment of the present invention.
[0014] FIG. 6 illustrates a diffuser on the back side of the PV unit, in accordance with an embodiment of the present invention.
[0015] FIG. 7 illustrates dielectric particles and white paint functioning as the diffuser of FIG. 6, in accordance with an embodiment of the present invention.
[0016] FIG. 8 illustrates metal particles functioning as the diffuser of FIG. 6, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0017] Embodiments of the present invention provide techniques and apparatus for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells.
AN EXEMPLARY PHOTOVOLTAIC UNIT
[0018] FIG. 1 illustrates various epitaxial layers of a photovoltaic (PV) unit 100 in cross-section. The various layers may be formed using any suitable method for
semiconductor growth, such as molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD)1 on a substrate (not shown).
[0019] The PV unit 100 may comprise a window layer 106 formed above the substrate and any underlying buffer layer(s). The window layer 106 may comprise aluminum gallium arsenide (AIGaAs), such as Alo.3Gao.7As. The window layer 106 may be undoped. The window layer 106 may be transparent to allow photons to pass through the window layer on the front side of the PV unit to other underlying layers.
[0020] A base layer 108 may be formed above the window layer 106. The base layer 108 may comprise any suitable group MI-V compound semiconductor, such as GaAs. The base layer 108 may be monocrystalline and may be n-doped.
[0021] As illustrated in FIG. 1 , an emitter layer 110 may be formed above the base layer 108. The emitter layer 110 may comprise any suitable group MI-V compound semiconductor for forming a heterojunction with the base layer 108. For example, if the base layer 108 comprises GaAs, the emitter layer 110 may comprise a different semiconductor material, such as AIGaAs (e.g., Alo.3Gao.7As). If the emitter layer 110 and the window layer 106 both comprise AIGaAs, the AlxGa-i-xAs composition of the emitter layer 110 may be the same as or different than the AlyGa-ι-yAs composition of the window layer. The emitter layer 110 may be monocrystalline and may be heavily p-doped (i.e., p+-doped). The combination of the base layer 108 and the emitter layer 110 may form an absorber layer for absorbing photons.
[0022] The contact of an n-doped base layer to a p+-doped emitter layer creates a p-n layer 112. When light is absorbed near the p-n layer 112 to produce electron- hole pairs, the built-in electric field may force the holes to the p+-doped side and the electrons to the n-doped side. This displacement of free charges results in a voltage difference between the two layers 108, 110 such that electron current may flow when a load is connected across terminals coupled to these layers.
[0023] Rather than an n-doped base layer 108 and a p+-doped emitter layer 110 as described above, conventional photovoltaic semiconductor devices typically have a p-doped base layer and an n+-doped emitter layer. The base layer is typically p- doped in conventional devices due to the diffusion length of the carriers.
[0024] Once the emitter layer 110 has been formed, cavities or recesses 114 may be formed in the emitter layer deep enough to reach the underlying base layer 108. Such recesses 114 may be formed by applying a mask to the emitter layer 110 using photolithography, for example, and removing the semiconductor material in the emitter layer 110 not covered by the mask using any suitable technique, such as wet or dry etching. In this manner, the base layer 108 may be accessed via the back side of the PV unit iOO.
[0025] For some embodiments, an interface layer 116 may be formed above the emitter layer 110. The interface layer 116 may comprise any suitable group Hl-V compound semiconductor, such as GaAs. The interface layer 116 may be p+-doped.
[0026] Once the epitaxial layers have been formed, the functional layers of the PV unit 100 (e.g., the window layer 106, the base layer 108, and the emitter layer 110) may be separated from the buffer layer(s) 102 and substrate during an epitaxial lift-off (ELO) process.
EXEMPLARY LIGHT TRAPPING
[0027] To achieve efficiency, the absorber layer of an ideal photovoltaic (PV) device would absorb all of the photons impinging on the PV device's front side facing the light source since the open circuit voltage (Voc) or short circuit current (/JC) is proportional to the light intensity. However, several loss mechanisms typically interfere with the PV device's absorber layer seeing or absorbing all of the light reaching the front side of the device. For example, the semiconductor layers of the PV device may be shiny (especially when made of pure silicon) and, therefore, may
reflect a substantial portion of the impinging photons, preventing these photons from ever reaching the absorber layer. If two semiconductor layers (e.g., the window layer and the base layer) have a different index of refraction, some of the photons reaching the interface between these two layers may be reflected according to Snell's Law if their angle of incidence is too high, again preventing these photons from reaching the absorber layer. Furthermore, the absorber layer may not absorb all of the impinging photons; some photons may pass through the absorber layer without affecting any electron-hole pairs.
[0028] Accordingly, there is a need for techniques and apparatus to capture the light impinging on the front side of the PV device such that as many photons as possible may be absorbed by the absorber layer and converted into electric energy. In this manner, the PV device's efficiency may be increased.
[0029] Apparatus for trapping the light within the semiconductor layers of a PV device may be divided into two categories: front side light trapping and back side light trapping. By employing both types of light trapping in a PV device, the idea is that nearly all photons impinging on the PV device's front side may be captured and "bounce around" within the semiconductor layers until the photons are absorbed by the absorber layer and converted to electric energy.
EXEMPLARY FRONT SIDE LIGHT TRAPPING
[0030] FIG. 2 illustrates an antireflective (AR) coating 802 disposed adjacent to the window layer 106 on the front side of the PV unit 100, in accordance with an embodiment of the present invention. According to its purpose, the AR coating 802 may comprise any suitable material that allows light to pass through while preventing light reflection from its surface. For example, the AR coating 802 may comprise magnesium fluoride (MgF2), zinc sulfide (ZnS), silicon nitride (SiN), titanium dioxide (Tiθ2), silicon dioxide (Siθ2), or any combination thereof. The AR coating 802 may be applied to the window layer 106 by any suitable technique, such as sputtering.
[0031] For some embodiments, the window layer 106 may be roughened or textured before applying the antireflective coating 802. FIG. 3 illustrates a roughened window layer 106. Roughening of the window layer 106 may be accomplished by wet etching or dry etching, for example. Texturing may be achieved by applying small particles, such as polystyrene spheres, to the surface of the window layer 106 before applying the AR coating 802. By roughening or texturing the window layer 106, different angles are provided at the interface between the AR coating 802 and the window layer, which may have different indices of refraction. In this manner, more of the incident photons may be transmitted into the window layer 106 rather than reflected from the interface between the AR coating 802 and the window layer because some photons' angles of incidence are too high according to Snell's Law. Thus, roughening or texturing the window layer 106 may provide increased light trapping.
[0032] Also for some embodiments, the window layer 106 may comprise multiple window layers. For these embodiments, the outermost window layer (i.e., the window layer closest to the front side of the PV unit 100) may be roughened or textured as described above before the antireflective coating 802 is applied, as illustrated in FIG. 4. In FIG. 4, the window layer 106 comprises a first window layer 1002 disposed adjacent to the base layer 108 and a second window layer 1004 interposed between the first window layer 1002 and the antireflective coating 802. The first and second window layers 1002, 1004 may comprise any material suitable for the window layer 106 as described above, such as AIGaAs, but typically with different compositions. For example, the first window layer 1002 may comprise Alo.3Gao.7As, and the second window layer 1004 may comprise Alo.1Gao.9As. Furthermore, some of the multiple window layers may be doped, while others are undoped for some embodiments. For example, the first window layer 1002 may be doped, and the second window layer 1004 may be undoped.
EXEMPLARY BACK SIDE LIGHT TRAPPING
[0033] For some embodiments, the emitter layer 110 on the back side of the PV unit 100 may be roughened or textured, as described above with respect to the front side, in an effort to increase light trapping. FIG. 5 illustrates such a roughened emitter layer 110.
[0034] FIG. 6 illustrates a diffuser 1202 on the back side of the PV unit 100 in an effort to increase the amount of light captured by the absorber layer. Rather than reflecting photons similar to a mirror where the angle of reflectance equals the angle of incidence, the purpose of the diffuser 1202 is to diffuse or scatter photons that pass through the absorber layer without being absorbed. For some embodiments, the diffuser 1202 may be covered with a reflective layer 1204. In this manner, the diffuser 1202 may provide new angles to incident photons, some of which may be redirected back to the interior of the PV unit. For other photons that are directed to the back side of the PV unit, the reflective layer 1204 may redirect these photons back through the diffuser 1202 and towards the interior of the PV unit. Although some of the light may be absorbed by the diffuser 1202 as the photons are scattered and redirected inside, much of the light is redirected to the absorber layer to be absorbed and converted into electric energy, thereby increasing efficiency. Conventional PV devices without a diffuser and a reflective layer may not be able to recapture photons that reach the back side of the device without being absorbed initially by the absorber layer.
[0035] For some embodiments, the diffuser 1202 may comprise dielectric particles 1302, as illustrated in FIG. 7. The dielectric particles may comprise any suitable material which is electrically insulative and does not absorb light. The dielectric particles 1302 may have a diameter in range from about 0.2 to 2.0 μm. The dielectric particles 1302 may be covered by white paint 1304, which reflects light and may act
as the reflective layer for redirecting photons back to the interior of the PV unit 100. The white paint 1304 may comprise TΪO2, for example.
[0036] For some embodiments, the diffuser 1202 may comprise metal particles 1402, as illustrated in FIG. 8. The metal particles 1402 may reflect photons that were not absorbed by the absorber layer, and by having a multitude of metal particles 1402, the photons may be scattered in different directions several times before being redirected to the interior of the PV unit 100. The metal particles 1402 may have a diameter of about 150 to 200 nm, functioning as relatively compact scatterers. With thinner particles in the diffuser 1202, the thickness of the PV unit 100 may be kept smaller, thereby maintaining the desired flexibility of the PV unit 100.
[0037] Because the metal particles 1402 are electrically conductive, lateral surfaces of the interface layer 116 may be passivated to prevent the metal particles 1402 from interfering with the operation of the device. The interface layer 116 may be passivated using any suitable passivation method, such as chemical vapor deposition (CVD) or plasma-enhanced CVD (PECVD). The passivation 1404 may comprise any suitable electrically non-conductive material, such as silicon nitride (SiN), SiOx, TiOx, TaOx, zinc sulfide (ZnS), or any combination thereof. Furthermore, for some embodiments, a dielectric layer 1406 may be formed above the metal particles 1402 in an effort to avoid shunting any back side contacts, as depicted in FIG. 8. The dielectric layer 1406 may comprise any suitable electrically insulative material, such as Siθ2, SiN, or glass.
[0038] While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims
1. A photovoltaic (PV) device, comprising: a p+-doped layer; an n-doped layer disposed above the p+-doped layer to form a p-n layer such that electric energy is created when photons are absorbed by the p-n layer; a window layer disposed above the n-doped layer; and an antireflective coating disposed above the window layer.
2. The PV device of claim 1 , wherein the p-n layer comprises a heterojunction.
3. The PV device of claim 1 , wherein the n-doped layer or the p+-doped layer comprises a group Nl-V semiconductor.
4. The PV device of claim 3, wherein the group Ml-V semiconductor is monocrystalline.
5. The PV device of claim 3, wherein the n-doped layer comprises n-GaAs.
6. The PV device of claim 3, wherein the p+-doped layer comprises P+-AIGaAs.
7. The PV device of claim 6, wherein the p+-doped layer comprises p+- Alo.3Gao.7As.
8. The PV device of claim 1 , wherein the window layer comprises AIGaAs.
9. The PV device of claim 8, wherein the window layer comprises Alo.3Gao.7As.
10. The PV device of claim 1 , wherein the window layer has a thickness of about 20 nm.
11. The PV device of claim 1 , wherein the antireflective coating comprises MgF2, ZnS, SiN, Tiθ2, SiC>2, or any combination thereof.
12. The PV device of claim 1 , wherein a surface of the window layer adjacent to the antireflective coating has been roughened to provide different angles for increased light trapping.
13. The PV device of claim 1 , further comprising particles interposed between the window layer and the antireflective coating to provide different angles for increased light trapping.
14. The PV device of claim 13, wherein the particles comprise polystyrene spheres.
15. The PV device of claim 1 , wherein the window layer comprises: a first window layer disposed above the n-doped layer; and a second window layer disposed above the first window layer.
16. The PV device of claim 15, wherein the first window layer and the second window layer comprise AIGaAs, but with different compositions.
17. The PV device of claim 15, wherein the first window layer is doped and the second window layer is undoped.
18. The PV device of claim 15, wherein a surface of the second window layer adjacent to the antireflective coating has been roughened to provide different angles for increased light trapping.
19. The PV device of claim 15, further comprising particles interposed between the second window layer and the antireflective coating to provide different angles for increased light trapping.
20. The PV device of claim 1 , wherein a bottom surface of the p+-doped layer has been roughened to provide different angles for increased light trapping.
21. The PV device of claim 1 , further comprising particles disposed below the p+- doped layer to provide different angles for increased light trapping.
22. The PV device of claim 21 , wherein the particles comprise polystyrene spheres.
23. A photovoltaic (PV) device, comprising: a p+-doped layer; an n-doped layer disposed above the p+-doped layer to form a p-n layer such that electric energy is created when light is absorbed by the p-n layer; a window layer disposed above the n-doped layer; and a diffuser disposed below the p+-doped layer.
24. The PV device of claim 23, wherein the p-n layer comprises a heterojunction.
25. The PV device of claim 23, wherein the n-doped layer or the p+-doped layer comprises a group Ml-V semiconductor.
26. The PV device of claim 25, wherein the group IM-V semiconductor is monocrystalline.
27. The PV device of claim 25, wherein the n-doped layer comprises n-GaAs.
28. The PV device of claim 25, wherein the p+-doped layer comprises P+-AIGaAs.
29. The PV device of claim 28, wherein the p+-doped layer comprises p+- Alo.3Gao.7As.
30. The PV device of claim 23, wherein the diffuser comprises a plurality of dielectric particles.
31. The PV device of claim 30, wherein the plurality of dielectric particles are covered with white paint.
32. The PV device of claim 31 , wherein the white paint comprises Tiθ2.
33. The PV device of claim 30, wherein the dielectric particles have diameters of about 0.2 to 2.0 μm.
34. The PV device of claim 23, wherein the diffuser comprises a plurality of metal particles.
35. The PV device of claim 34, wherein the metal particles have diameters of about 150 to 200 nm.
36. The PV device of claim 34, further comprising a dielectric layer disposed below the metal particles.
37. The PV device of claim 36, wherein the dielectric layer comprises Siθ2, SiN, or glass.
38. The PV device of claim 23, further comprising a reflective layer disposed below the diffuser.
39. The PV device of claim 23, wherein the window layer comprises AIGaAs.
40. The PV device of claim 39, wherein the window layer comprises Alo.3Gao.7As.
41. The PV device of claim 23, wherein the window layer has a thickness of about 20 nm.
42. The PV device of claim 23, wherein a bottom surface of the p+-doped layer has been roughened to provide different angles for increased light trapping.
43. The PV device of claim 23, further comprising particles disposed below the p+- doped layer to provide different angles for increased light trapping.
44. The PV device of claim 43, wherein the particles comprise polystyrene spheres.
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106374001A (en) * | 2015-07-20 | 2017-02-01 | 中国科学院苏州纳米技术与纳米仿生研究所 | GaAs thin-film solar cell having tapered back scattering layer and preparation method thereof |
Families Citing this family (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8772628B2 (en) | 2004-12-30 | 2014-07-08 | Alliance For Sustainable Energy, Llc | High performance, high bandgap, lattice-mismatched, GaInP solar cells |
TW201029196A (en) * | 2008-10-23 | 2010-08-01 | Alta Devices Inc | Thin absorber layer of a photovoltaic device |
WO2010048547A2 (en) * | 2008-10-23 | 2010-04-29 | Alta Devices, Inc. | Photovoltaic device with increased light trapping |
CN102257628A (en) * | 2008-10-23 | 2011-11-23 | 奥塔装置公司 | Integration of a photovoltaic device |
US20120104460A1 (en) | 2010-11-03 | 2012-05-03 | Alta Devices, Inc. | Optoelectronic devices including heterojunction |
US8937244B2 (en) * | 2008-10-23 | 2015-01-20 | Alta Devices, Inc. | Photovoltaic device |
EP2351099A2 (en) * | 2008-10-23 | 2011-08-03 | Alta Devices, Inc. | Photovoltaic device with back side contacts |
US9691921B2 (en) | 2009-10-14 | 2017-06-27 | Alta Devices, Inc. | Textured metallic back reflector |
US20160155881A1 (en) * | 2009-10-23 | 2016-06-02 | Alta Devices, Inc. | Thin film iii-v optoelectronic device optimized for non-solar illumination sources |
US20150380576A1 (en) | 2010-10-13 | 2015-12-31 | Alta Devices, Inc. | Optoelectronic device with dielectric layer and method of manufacture |
US11271128B2 (en) | 2009-10-23 | 2022-03-08 | Utica Leaseco, Llc | Multi-junction optoelectronic device |
US20170141256A1 (en) | 2009-10-23 | 2017-05-18 | Alta Devices, Inc. | Multi-junction optoelectronic device with group iv semiconductor as a bottom junction |
US9768329B1 (en) | 2009-10-23 | 2017-09-19 | Alta Devices, Inc. | Multi-junction optoelectronic device |
US20130270589A1 (en) * | 2012-04-13 | 2013-10-17 | Alta Devices, Inc. | Optoelectronic device with non-continuous back contacts |
US9502594B2 (en) | 2012-01-19 | 2016-11-22 | Alta Devices, Inc. | Thin-film semiconductor optoelectronic device with textured front and/or back surface prepared from template layer and etching |
US20120305059A1 (en) * | 2011-06-06 | 2012-12-06 | Alta Devices, Inc. | Photon recycling in an optoelectronic device |
US9397238B2 (en) | 2011-09-19 | 2016-07-19 | First Solar, Inc. | Method of etching a semiconductor layer of a photovoltaic device |
US11038080B2 (en) | 2012-01-19 | 2021-06-15 | Utica Leaseco, Llc | Thin-film semiconductor optoelectronic device with textured front and/or back surface prepared from etching |
CN103474504B (en) * | 2012-06-06 | 2016-09-07 | 浙江昱辉阳光能源江苏有限公司 | A kind of prepare the method for reflectance coating, solar panel and crystal silicon chip thereof |
GB201215344D0 (en) | 2012-08-29 | 2012-10-10 | Ibm | Light-reflecting grating structure for photvoltaic devices |
US9590131B2 (en) | 2013-03-27 | 2017-03-07 | Alliance For Sustainable Energy, Llc | Systems and methods for advanced ultra-high-performance InP solar cells |
CN104795454B (en) * | 2014-12-26 | 2017-05-03 | 天津蓝天太阳科技有限公司 | Gallium arsenide solar cell top cell window layer nano cone structure and preparation method thereof |
GR20150100472A (en) * | 2015-10-30 | 2017-07-03 | Πανεπιστημιο Πατρων | Polycrystalline silicon water with configured microstructures on their surfaces for improving solar absorption |
RU170349U1 (en) * | 2016-11-07 | 2017-04-21 | Федеральное государственное бюджетное учреждение науки Физико-технический институт им. А.Ф. Иоффе Российской академии наук | GaAs-Based Photoconverter |
RU2646547C1 (en) * | 2016-11-22 | 2018-03-05 | Федеральное государственное бюджетное учреждение науки Физико-технический институт им. А.Ф. Иоффе Российской академии наук | Laser radiation photoconverter |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0595634A1 (en) * | 1992-10-30 | 1994-05-04 | Spectrolab, Inc. | Gallium arsenide/aluminum gallium arsenide photocell including environmentally sealed ohmic contact grid interface and method of fabricating the cell |
US20010027805A1 (en) * | 1998-05-28 | 2001-10-11 | Frank Ho | Solar cell having an integral monolithically grown bypass diode |
WO2002065553A1 (en) * | 2001-02-09 | 2002-08-22 | Midwest Research Institute | Isoelectronic co-doping |
US20070277874A1 (en) * | 2006-05-31 | 2007-12-06 | David Francis Dawson-Elli | Thin film photovoltaic structure |
Family Cites Families (59)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4017332A (en) | 1975-02-27 | 1977-04-12 | Varian Associates | Solar cells employing stacked opposite conductivity layers |
US4107723A (en) | 1977-05-02 | 1978-08-15 | Hughes Aircraft Company | High bandgap window layer for GaAs solar cells and fabrication process therefor |
US4094704A (en) | 1977-05-11 | 1978-06-13 | Milnes Arthur G | Dual electrically insulated solar cells |
FR2404307A1 (en) | 1977-09-27 | 1979-04-20 | Centre Nat Etd Spatiales | DOUBLE HETEROJUNCTION SOLAR CELLS AND MOUNTING DEVICE |
US4197141A (en) | 1978-01-31 | 1980-04-08 | Massachusetts Institute Of Technology | Method for passivating imperfections in semiconductor materials |
US4410758A (en) | 1979-03-29 | 1983-10-18 | Solar Voltaic, Inc. | Photovoltaic products and processes |
US4295002A (en) | 1980-06-23 | 1981-10-13 | International Business Machines Corporation | Heterojunction V-groove multijunction solar cell |
US4444992A (en) | 1980-11-12 | 1984-04-24 | Massachusetts Institute Of Technology | Photovoltaic-thermal collectors |
US4338480A (en) | 1980-12-29 | 1982-07-06 | Varian Associates, Inc. | Stacked multijunction photovoltaic converters |
US4400221A (en) | 1981-07-08 | 1983-08-23 | The United States Of America As Represented By The Secretary Of The Air Force | Fabrication of gallium arsenide-germanium heteroface junction device |
US4385198A (en) * | 1981-07-08 | 1983-05-24 | The United States Of America As Represented By The Secretary Of The Air Force | Gallium arsenide-germanium heteroface junction device |
US4419533A (en) * | 1982-03-03 | 1983-12-06 | Energy Conversion Devices, Inc. | Photovoltaic device having incident radiation directing means for total internal reflection |
US4479027A (en) | 1982-09-24 | 1984-10-23 | Todorof William J | Multi-layer thin-film, flexible silicon alloy photovoltaic cell |
US4497974A (en) | 1982-11-22 | 1985-02-05 | Exxon Research & Engineering Co. | Realization of a thin film solar cell with a detached reflector |
US4633030A (en) | 1985-08-05 | 1986-12-30 | Holobeam, Inc. | Photovoltaic cells on lattice-mismatched crystal substrates |
US4667059A (en) | 1985-10-22 | 1987-05-19 | The United States Of America As Represented By The United States Department Of Energy | Current and lattice matched tandem solar cell |
JP2732524B2 (en) | 1987-07-08 | 1998-03-30 | 株式会社日立製作所 | Photoelectric conversion device |
US5116427A (en) * | 1987-08-20 | 1992-05-26 | Kopin Corporation | High temperature photovoltaic cell |
US4889656A (en) | 1987-10-30 | 1989-12-26 | Minnesota Mining And Manufacturing Company | Perfluoro(cycloaliphatic methyleneoxyalkylene) carbonyl fluorides and derivatives thereof |
US4989059A (en) * | 1988-05-13 | 1991-01-29 | Mobil Solar Energy Corporation | Solar cell with trench through pn junction |
JPH02135786A (en) | 1988-11-16 | 1990-05-24 | Mitsubishi Electric Corp | Solar battery cell |
US5217539A (en) | 1991-09-05 | 1993-06-08 | The Boeing Company | III-V solar cells and doping processes |
US5223043A (en) | 1991-02-11 | 1993-06-29 | The United States Of America As Represented By The United States Department Of Energy | Current-matched high-efficiency, multijunction monolithic solar cells |
US5385960A (en) | 1991-12-03 | 1995-01-31 | Rohm And Haas Company | Process for controlling adsorption of polymeric latex on titanium dioxide |
US5342453A (en) | 1992-11-13 | 1994-08-30 | Midwest Research Institute | Heterojunction solar cell |
US5316593A (en) | 1992-11-16 | 1994-05-31 | Midwest Research Institute | Heterojunction solar cell with passivated emitter surface |
EP0617303A1 (en) | 1993-03-19 | 1994-09-28 | Akzo Nobel N.V. | A method of integrating a semiconductor component with a polymeric optical waveguide component, and an electro-optical device comprising an integrated structure so attainable |
US5376185A (en) | 1993-05-12 | 1994-12-27 | Midwest Research Institute | Single-junction solar cells with the optimum band gap for terrestrial concentrator applications |
US6166218A (en) | 1996-11-07 | 2000-12-26 | Ciba Specialty Chemicals Corporation | Benzotriazole UV absorbers having enhanced durability |
DE69828936T2 (en) | 1997-10-27 | 2006-04-13 | Sharp K.K. | Photoelectric converter and its manufacturing method |
US6231931B1 (en) | 1998-03-02 | 2001-05-15 | John S. Blazey | Method of coating a substrate with a structural polymer overlay |
US6166318A (en) | 1998-03-03 | 2000-12-26 | Interface Studies, Inc. | Single absorber layer radiated energy conversion device |
US6103970A (en) | 1998-08-20 | 2000-08-15 | Tecstar Power Systems, Inc. | Solar cell having a front-mounted bypass diode |
US6229084B1 (en) | 1998-09-28 | 2001-05-08 | Sharp Kabushiki Kaisha | Space solar cell |
US6150603A (en) | 1999-04-23 | 2000-11-21 | Hughes Electronics Corporation | Bilayer passivation structure for photovoltaic cells |
JP2001127326A (en) * | 1999-08-13 | 2001-05-11 | Oki Electric Ind Co Ltd | Semiconductor substrate, method of manufacturing the same, solar cell using the same and manufacturing method thereof |
US6368929B1 (en) | 2000-08-17 | 2002-04-09 | Motorola, Inc. | Method of manufacturing a semiconductor component and semiconductor component thereof |
US20030070707A1 (en) | 2001-10-12 | 2003-04-17 | King Richard Roland | Wide-bandgap, lattice-mismatched window layer for a solar energy conversion device |
US6864414B2 (en) | 2001-10-24 | 2005-03-08 | Emcore Corporation | Apparatus and method for integral bypass diode in solar cells |
WO2003073517A1 (en) | 2002-02-27 | 2003-09-04 | Midwest Research Institute | Monolithic photovoltaic energy conversion device |
US8067687B2 (en) | 2002-05-21 | 2011-11-29 | Alliance For Sustainable Energy, Llc | High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy converters |
TW538481B (en) | 2002-06-04 | 2003-06-21 | Univ Nat Cheng Kung | InGaP/AlGaAs/GaAs hetero-junction bipolar transistor with zero conduction band discontinuity |
US20060162767A1 (en) | 2002-08-16 | 2006-07-27 | Angelo Mascarenhas | Multi-junction, monolithic solar cell with active silicon substrate |
US8664525B2 (en) * | 2003-05-07 | 2014-03-04 | Imec | Germanium solar cell and method for the production thereof |
TWI261934B (en) | 2003-09-09 | 2006-09-11 | Asahi Kasei Emd Corp | Infrared sensing IC, infrared sensor and method for producing the same |
US7566948B2 (en) | 2004-10-20 | 2009-07-28 | Kopin Corporation | Bipolar transistor with enhanced base transport |
US7375378B2 (en) * | 2005-05-12 | 2008-05-20 | General Electric Company | Surface passivated photovoltaic devices |
US10069026B2 (en) | 2005-12-19 | 2018-09-04 | The Boeing Company | Reduced band gap absorber for solar cells |
US20080245409A1 (en) | 2006-12-27 | 2008-10-09 | Emcore Corporation | Inverted Metamorphic Solar Cell Mounted on Flexible Film |
US20100006143A1 (en) | 2007-04-26 | 2010-01-14 | Welser Roger E | Solar Cell Devices |
US8193609B2 (en) | 2008-05-15 | 2012-06-05 | Triquint Semiconductor, Inc. | Heterojunction bipolar transistor device with electrostatic discharge ruggedness |
US8866005B2 (en) | 2008-10-17 | 2014-10-21 | Kopin Corporation | InGaP heterojunction barrier solar cells |
TW201029196A (en) | 2008-10-23 | 2010-08-01 | Alta Devices Inc | Thin absorber layer of a photovoltaic device |
CN102257628A (en) | 2008-10-23 | 2011-11-23 | 奥塔装置公司 | Integration of a photovoltaic device |
EP2351099A2 (en) | 2008-10-23 | 2011-08-03 | Alta Devices, Inc. | Photovoltaic device with back side contacts |
US8937244B2 (en) | 2008-10-23 | 2015-01-20 | Alta Devices, Inc. | Photovoltaic device |
WO2010048547A2 (en) | 2008-10-23 | 2010-04-29 | Alta Devices, Inc. | Photovoltaic device with increased light trapping |
US20100132774A1 (en) | 2008-12-11 | 2010-06-03 | Applied Materials, Inc. | Thin Film Silicon Solar Cell Device With Amorphous Window Layer |
US8642883B2 (en) | 2010-08-09 | 2014-02-04 | The Boeing Company | Heterojunction solar cell |
-
2009
- 2009-10-23 WO PCT/US2009/061911 patent/WO2010048547A2/en active Application Filing
- 2009-10-23 TW TW98136016A patent/TW201031006A/en unknown
- 2009-10-23 US US12/605,140 patent/US8686284B2/en active Active
-
2010
- 2010-11-05 US US12/940,966 patent/US8895847B2/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0595634A1 (en) * | 1992-10-30 | 1994-05-04 | Spectrolab, Inc. | Gallium arsenide/aluminum gallium arsenide photocell including environmentally sealed ohmic contact grid interface and method of fabricating the cell |
US20010027805A1 (en) * | 1998-05-28 | 2001-10-11 | Frank Ho | Solar cell having an integral monolithically grown bypass diode |
WO2002065553A1 (en) * | 2001-02-09 | 2002-08-22 | Midwest Research Institute | Isoelectronic co-doping |
US20070277874A1 (en) * | 2006-05-31 | 2007-12-06 | David Francis Dawson-Elli | Thin film photovoltaic structure |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106374001A (en) * | 2015-07-20 | 2017-02-01 | 中国科学院苏州纳米技术与纳米仿生研究所 | GaAs thin-film solar cell having tapered back scattering layer and preparation method thereof |
CN106374001B (en) * | 2015-07-20 | 2018-01-09 | 中国科学院苏州纳米技术与纳米仿生研究所 | GaAs thin film solar cells with taper back-scattering layer and preparation method thereof |
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US20100126571A1 (en) | 2010-05-27 |
US8895847B2 (en) | 2014-11-25 |
TW201031006A (en) | 2010-08-16 |
US8686284B2 (en) | 2014-04-01 |
WO2010048547A3 (en) | 2010-07-22 |
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