LIGHT-EMITTING SEMICONDUCTOR DEVICE

摘要

1316475 Semi-conductor light sources GENERAL ELECTRIC CO 4 Nov 1970 [12 Nov 1969] 52537/70 Heading H1K [Also in Division C4] A semi-conductor structure contains two or more pn-junctions which may each be forward biased in any combination, the light emitted by the forward-biased junctions being of different colours. The various layers are of AIIIBV material containing gallium and phosphorus, and at least an outermost one comprises as host material gallium aluminium phosphide. In the structure shown layer P 1 is of gallium phosphide doped with zinc and oxygen (deep level), layer N 1 is of gallium phosphide doped with tellurium, layer N 3 is of gallium aluminium phosphide doped with aluminium, and layer P 2 is of gallium aluminium phosphide predominantly doped with aluminium. J 1 emits green light (which is not absorbed by N 2 and P 2 because of the larger band gap of the gallium aluminium phosphide) and J 2 emits red light. Layer P 1 is confined in extent so that the areas of J 1 and J 2 are equal to thus ensure a good perceived yellow when the junctions are energized together. In variants the junction areas need not be equal or there may be three superposed junctions (each with its own colour), any combination of which may be energized.