Time Dependence and Excitation-Intensity Dependence of Luminescence in CdTe

Abstract

Transient behavior of luminescence has been measured in high-purity CdTe in the 17–82 K temperature range using a mode-locked Kr⁺ laser as the excitation source. The presence of the bottleneck of the excitonic polariton has been clearly observed in the wavelength dependence of the luminescence decay time. It has also been found that when the excitation density is varied, the spectral shape as well as the efficiency of the polariton luminescence change, while the decay time remains almost constant. Mechanisms of the relaxation following the photo-excitation are discussed.