Miscibility of III-V Semiconductors Studied by Flash Evaporation

Abstract

A study has been made of the mutual solid solubility of the phosphides, arsenides, and antimonides of gallium and indium, all of which crystallize in the zinc‐blende structure. The films were prepared by flash evaporation of mixed powders. X‐ray diffraction analysis of the films showed that all of the phosphides and arsenides form a complete range of solid solutions, while the phosphides and antimonides are largely immiscible. In the arsenide‐antimonide systems, only those containing a common group III element are completely miscible (e.g., InAs–InSb, GaAs–GaSb). All quasibinary systems with a common group V element form a complete range of solid solutions. The results have been extrapolated to give a schematic representation of the limits of solubility in the multicomponent system In–Ga–P–As–Sb. The solubility has been correlated with the size of the component atoms involved in each system. Where solid solution occurred, the lattice constants were found to obey Vegard's law within the limits of accuracy. Epitaxy was achieved by depositing the films onto single‐crystal germanium. Optical absorption has been measured on films covering a wide range of compositions.