| 摘要 |
1,222,527. Electroluminescence. NIPPON ELECTRIC CO. Ltd. 27 Feb., 1968 [27 Feb., 1967], No. 9328/68. Heading C4S. [Also in Division H1] A light emitting device comprises a semiconductor crystal having a P-type region and an N-type region defining between them a PN- junction, that part of the P-type region adjacent the junction being more strongly doped than the remainder to form a P+ region whose width is substantially equal to the diffusion length of carriers injected from the junction, so that when the device is forward biased recombination radiation occurs in the strongly doped region where the light emission efficiency is high. The semiconductor material may be gallium arsenide, indium arsenide, indium antimonide or gallium phosphide, the crystal being grown from solutions in stages to provide the doped regions. The dopants used are zinc and tellurium. The device is completed by etching and polishing steps. Such a device may be a light-emitting diode, Fig. 5, with P-type region 51, P+-type region 52 and N-type region 53. An electrode 54 and counter electrode 55 are formed by sintering non-electrolytically plated nickel areas. A reflecting area may be employed to increase the efficiency of the light output by polishing either the top or bottom surface into a mirror face and plating with silver, so that all the light is emitted from one surface only, Fig. 6, not shown. A plurality of devices may be made within a single pellet and further an N + -type layer may be provided in addition to the P + -type layer. |
