Disclosed herein are (1) a light-emitting semiconductor device that uses a gallium nitride compound semiconductor (AlxGa1xN) in which the n-layer of n-type gallium nitride compound semiconductor (AlxGa1xN) is of double-layer structure including an n-layer of low carrier concentration and an n-layer of...http://www.google.de/patents/US6593599?utm_source=gb-gplus-sharePatent US6593599 - Light-emitting semiconductor device using gallium nitride group compound
