Pico-Second Time Dependence of Luminescence Line Due to Exciton-Exciton Collision in CdSe

Abstract

Experimental data for the pico-second time dependence of the P line luminescence due to the inelastic exciton-exciton collision in CdSe, described in the authors’ previous paper, are analyzed, using simple rate equations which are based on the assumption that the dependence is dominated by the light amplification effect due to stimulated emission. It is shown that observed time dependence curves are well reproduced by choosing suitable values for the parameters. Changes in the time dependence with excitation density are attributed to changes in optical gain. It is supposed that the optical gain for the P line is proportional to the square of excitation density, presenting further confirmation for the assignment of the P line. Changes with changing observation direction are reasonably interpreted by considering the relation between the manner of the light amplification and the observation direction.