Compensation and carrier trapping in indium-doped CdTe: Contributions from an important near-mid-gap donor

Abstract

We report on the recharging of the neutral state of a deep-donor layer that increases the efficiency of charge collection in detector-grade CdTe:In. Measurements with photoinduced current transient spectroscopy and thermoelectric effect spectroscopy revealed positively charged energy level at EC−0.65 eV. Photoluminescence measurements identified this level being responsible for the 0.68 eV emission band. Its positive charge is converted into a neutral one by the upward displacement of Fermi level. We discuss the nature of this deep defect based on the latest ab initio calculations.