Photoluminescence spectra of doped n-type indium antimonide crystals

Abstract

This paper presents a detailed study of photoluminescence of doped indium antimonide crystals. We have conducted a detailed study of photoluminescence of doped n-type indium antimonide crystals in a wide range of concentrations 1*1015 cm-3-1.5*1019 cm-3 at temperature 77 K. In this paper, we have for the first time obtained spectra of photoluminescence of indium antimonide with n > 5*1017 cm-3 and experimentally discovered that spectrum of photoluminescence of indium antimonide with n ≥ 8.5*1016 cm-3 consists of two lines, maxima of which shift towards higher energies with increasing concentration. It has been established that shortwave line of doped n-type indium antimonide crystals’ radiation is caused by recombination of electrons, located at Fermi level, with holes in valence band top. It has been shown that the best agreement between the experiment and theory in heavily doped crystals is reached by taking into account fluctuations of donor concentrations, dependence of the band gap on the degree of doping, as well as effective reduction of Fermi energy with increasing concentration.