Epitaxial indium-gallium-arsenide phosphide layer on lattice- matched indium-phosphide substrate and devices

摘要

An epitaxial layer of a quaternary III-V alloy of Ga, In, As, and P has its constituents proportioned for lattice matching to a substrate having a lattice constant falling within the range of 5.45 to 6. 05 A. In addition, the constituents of the alloy are proportioned to provide a selected bandgap energy falling within the range of 2.23 to 0. 35 electron volts; this corresponds to wavelengths of 0.55 to 3.5 microns. Near perfect lattice matched heterojunctions are provided between the epitaxial layer and the lattice matched substrate; these are useful for providing improved photocathodes and lasers, particularly in the infrared range of wavelengths between 0.8 and 2.0 microns.