Recombination processes in highly excited CdS

Abstract

Experimental results on the spontaneous and stimulated emission of CdS are presented in the temperature range from liquid‐helium temperature to room temperature under electron‐beam excitation. At temperatures below 100 K, the dominating laser process results from the exciton‐exciton interaction. In addition, lasing on the first and second phonon replica of the A₁ exciton has been observed. At temperatures above 100 K, the laser emission is found to shift to lower energies much stronger than that of the band gap. This shift can quantitatively be accounted for by the exciton‐electron interaction process.