Radiative recombination in PbTe quantum wells

Abstract

Recombination of quasi-two-dimensional (2D) free-electron-hole pairs in PbTe/(Pb,Eu)Te multiple quantum wells has been studied in time-resolved photoluminescence experiments in the 4–5 μm region on subnanosecond scale by an infrared upconversion method. Over a finite temperature range, the recombination rate is seen to vary approximately as 1/T, as expected for a radiative process in a nondegenerate 2D carrier gas. A model is presented where the recombination is enhanced by the presence of a substantial background hole density in the PbTe wells, generated in a manner analogous to modulation doping.