Recombination Centers in InSb

Abstract

A study has been made of the temperature dependence of the lifetime and Hall coefficient in p- and n-type InSb with extrinsic carrier concentrations ranging respectively from 1×1013 to 4×1015 cm–3 and from 2×1012 to 5×1014 cm–3, the lifetime having been measured by means of the phase-shift method. The lifetime data confirm that the interband Auger process is the limiting recombination process in InSb for temperatures above 150°K. Below 150°K both the lifetime and Hall data are generally consistent with a model consisting of two sets of single-level, donor-like recombination centers, rather than with a model of a single set of divalent, donor-like centers as used in a previous work. The energy levels of these centers are located at 0.071 eV and 0.11 eV above the valence band. Subsequent bombardment of a p-type and an n-type sample with 11-Mev electrons produced an increase in the number of recombination centers having the same properties as those occurring before bombardment. It is concluded that the recombination centers in as-grown crystals are lattice defects of a simple nature, and that there are grounds for believing that associated with the two energy levels are two different sets of defects rather than a single set.