| 摘要 |
1474942 Electroluminescence RACHARMAKADZE R I CHIKOVANI and Z I ALFEROV 2 May 1974 [28 May 1973 31 May 1973 12 June 1973] 19363/74 Heading C4S [Also in Division H1] A light emitting diode comprises a P+ type gallium arsenide substrate on which have successively been deposited P, compensated and N type layers of Al x Ga 1-x As, the P and N layers being doped with Zn and Te respectively and the compensated layer with both Zn and Te and the value of x lying between 0�3 and 0�37 in the P layer, between 0�4 and 0�65 in the N layer, and within 0�05 of that in the P layer in the compensated layer. As described the substrate and the N type layer are directly ohmically contacted by layers of Al, Ni, Cu, Sn, Ag, Au or alloys thereof. Alternatively an N + or N + and N + + layers may be disposed between the N type layer and its contact. The N, N+ and N+ + layers may each cover the whole or only part of the immediately underlying layer. Numerous examples are described with various layer and substrate thicknesses and doping and are preferably produced by liquid phase epitaxy from two melts of Ga, Al and As containing Zn and Te, and Te respectively. Initially the GaAs substrate is contacted by the Zn and Te containing melt and after a period of cooling to deposit the P type layer the other melt is added and cooling continued to deposit the compensated and N layers from the mixed melt the cooling rate being increased in two steps to provide the N + and N + + layers where required, any desired areal limitation of layers being achieved by selective etching. Processing details are given. |
