Radiative and Interfacial Recombination in CdTe Heterostructures

Abstract

Double heterostructures (DH) were produced consisting of a CdTe film between two wide band gap barriers of CdMgTe alloy. A combined method was developed to quantify radiative and non- radiative recombination rates by examining the dependence of photoluminescence (PL) on both ex- citation intensity and time. The measured PL characteristics, and the interface state density extracted by modeling, indicate that the radiative efficiency of CdMgTe/CdTe DHs is comparable to that of AlGaAs/GaAs DHs, with interface state densities in the low 1010 cm-2 and carrier life- times as long as 240 ns. The radiative recombination coefficient of CdTe is found to be near 10-10 cm3s-1. CdTe film growth on bulk CdTe substrates resulted in a homoepitaxial interface layer with a high non-radiative recombination rate.