Time‐Resolved Luminescence of Localized Excitons in CdS1—xSex under High Excitation

Abstract

AbstractThe temporal evolution of luminescence due to localized excitons in CdS1—xSex for various compositions from x = 0.02 to 0.55 is investigated after pulsed excitation (t ≈ 50 ps). The excitation intensity is varied from 8 × 105 W/cm2 up to 4 × 107 W/cm2. For the first time the luminescence dynamics is investigated under extremely high excitation into the extended states and it is found that the luminescence decay times, τD, become shorter and independent from the photon energy for high excitation. This behaviour is caused by the saturation of the localized states under high excitation. The x‐dependence of the “tailing parameter” and the total density of the localized states are discussed based on the experimental findings.