SEMICONDUCTOR LUMINESCENT DEVICES AND METHODS OF MAKING THEM

摘要

1359308 Electroluminescence WESTERN ELECTRIC CO Inc 24 June 1971 [30 June 1970] 29658/70 Heading C4S [Also in Division H1] An electroluminescent III-V semi-conductor body includes two portions forming a PN junction and having in at least one portion for a distance of a few diffusion lengths of minority carriers from the junction, a region in which the concentration of isoelectronic nitroged traps is substantially greater than in the remainder of that portion. The variation of concentration may be in both portions. The variation reduces absorption in regions away from the junction and higher electrical conductivity in the latter regions reduces heat losses. The traps may be nitrogen centres in a GaP host, the N and P type portions being S and Zn doped respectively or gallium nitride host with Te or Se dopants in the N portion and P type Cd dopants. The trap concentration near and away from the junction may be 1019 and 1018/c.c. respectively. Other concentrations are given and epitaxial growths of a four section device with substrate 11, and epitaxial layers 11À5, 12À5 and 12, described in detail, N being introduced from a 1/10% ammonia - hydrogen atmosphere, dimensions being disclosed. Layers 12, 12À5 may be grown as a single layer. Tin alloy contact 14, Au wire 15, and Au (2% Zn) alloy wire 16 are included. Substrate 11 may be formed epitaxially or by pulling. Absorption of emitted light is prevented by glass base 17 cemented by resin 18 of a refractive index to assist light beam emergence.