Auger ionization of semiconductor quantum drops in a glass matrix

Abstract

A microscopic model of degradation of both the nonlinear optical and luminescent properties of semiconductor-doped glasses is proposed. In the framework of the model the degradation is due to the process of Auger ionization of microcrystals when some electron-hole pairs are excited. The theoretical dependences of Auger ionization rate on the microcrystal size and energy band parameters of the glass/semiconductor heterostructures are obtained. The luminescence degradation kinetics have been studied in CdS microcrystals doped glasses with different average size at various pumping light intensities. The experimental dependences of the ionization rate on the microcrystal size and intensity are found to be in good agreement with the theoretical calculations. It is shown that an abrupt heterointerface leads to a strong increase of the Auger process rate. Oscillations of the Auger ionization probability and their dependences on the microcrystal size are predicted.