| 摘要 |
PURPOSE:To increase density of carriers at the area where electrons and positive holes are recombined by sandwiching one-conduction type 6H-SiC layer between 4H-SiC layer showing the same conductive type and 4H-SiC layer showing the reverse conductive type in reference to it. CONSTITUTION:Aluminum doped p-type 4H-SiC layer 12 and aluminum, nitrogen doped n-type 6H-SiC layer 13, and a nitrogen doped n-type 4H-SiC layer 14 are laminated on a p-type 4H-SiC substrate 11 in sequence and the first and second ohmic electrodes 15 and 16 are formed on the rear surface of a substrate 11 and the n-type 4H-SiC layer 14. It allows an electron 23 which is located at a conductive band 18 or a donor level 27 and a positive hole 24 which is located at an acceptor level 28 to be recombined in an n-type 6H-SiC layer 13, thus emitting a blue light with a wavelength of 480nm. At this time, since injection of the electron 23 into the p-type 4H-SiC layer 12 and that of the positive hole 24 into the n-type 4H-SiC layer are prevented by barriers 21 and 22, the n-type 6H-SiC layer 13 becomes an area where the electron 23 and positive hole 24 exist in high concentration. Thus, in the n-type 6H-SiC layer 13, recombination efficiency of the electron 23 and the positive hole 24 improves and as a result the emission efficiency improves. |
