Abstract: An epitaxial wafer of a compound semiconductor comprising a single crystalline semiconductor substrate consisting of GaP and an active layer consisting of GaAs.sub.1-x P.sub.x, having a mixed crystal ratio (x) in the range of from 0.5 to 1 is used for an LED. According to the present invention, between the single crystalline semiconductor substrate and the active layer, a light-absorbing layer consisting of GaAs.sub.1-x P.sub.x having the mixed crystal ratio (x) smaller than that of the active layer, is formed to suppress the reflection of light from the surface of the substrate.

Abstract: A method of manufacturing a mixed crystal compound semiconductor wafer suitable for the production of LED having a high light output. Upon a monocrystalline substrate of III-V semiconductor material a base layer is epitaxially grown of the same material as the substrate. An initial gradient layer is grown on the base layer having a mixed crystal ratio varying continuously from that of the base layer to a first value at a constant temperature. A combination sublayer is grown on the initial gradient sublayer which includes at least one constant sublayer having a constant crystal mixture ratio and at least one gradient sublayer having a crystal mixture ratio varying continuously between the mixed crystal ratios of its adjacent constant layers.

Abstract: An epitaxial wafer of GaAs.sub.1-x P.sub.x has been doped with nitrogen and used for the production of light emitting diode (LED). The carrier concentration of the conventional GaAs.sub.1-x P.sub.x was from 3.times.10.sup.16 to 2.times.10.sup.17 /cm.sup.3.According to the present invention, the carrier concentration is reduced lower than the conventional concentration and the luminance of LED is increased approximately two or three times the conventional luminance.

Abstract: An epitaxial layer of a photoelectric element, which is formed on a substrate and in which a p-n junction is formed has a high carrier density region adjacent the substrate, so that the provision of ohmic electrodes thereon is facilitated.

Abstract: A method of manufacturing an electroluminescent compound semiconductor wafer having epitaxial film layers each composed of a semiconductor containing components belonging to III and V groups of the periodic table one of which layers has the mixed crystal ratio of the components being constant comprises the step of at least reducing the supply of at least one of the III and V components at least once during the formation of the one layer.

Abstract: Semiconductor epitaxial wafers consisting of an epitaxial film and its substrate can be removed, in accordance with the present invention, from a substrate supporting component, without breaking the wafers into pieces after completion of vapor growth. The carbonaceous powder according to the present invention can greatly and effectively decrease the breaking of wafers, as compared with the conventional SiO.sub.2 or SiC-coated substrate supporting components.