Growth and properties of liquid-phase epitaxial GaAs1−xSbx

Abstract

A detailed study is presented of the Ga‐As‐Sb ternary phase diagram. Liquidus temperatures have been measured between 700 and 900 °C by direct observation of the solutions, and layers then grown epitaxially on GaAs substrates. The nonequilibrium effect of constitutional supercooling on the compositions of the grown layers is investigated. Solidus compositions, from layers slowly grown to minimize this effect, are used together with the liquidus data to fit a calculated phase diagram. These results lead to the conclusion that GaAs_1−xSb_x is a borderline case between miscible and immiscible solid solutions. An accurate determination of the ternary band gap has been made as a function of composition over the range 0⩽x⩽0.2. The room‐temperature electrical properties of undoped, Te‐doped (n‐type), and Ge‐doped (p‐type) epilayers have also been determined.