Influence of laser radiation on photoluminescence of CdTe

In the present study, we propose a new model for the process of generation of laser donor centres (LDC) and the creation of a potential barrier by las er radiation (LR) in semiconductors. According to this model the Thermograd ient effect, created by hot electrons, has the main role in the interaction process of LR and semiconductors. The state of the CdTe(Cl)-SiO2 interface under the influence of strongly absorbed powerful YAG:Nd laser irradiation has been studied. Such a state has been defined by measuring the current v oltage characteristics (CVC) in the external perpendicular magnetic field, the so-called magnetoconcentration effect, and photoluminescence method at low temperature. The rectifying type of CVC in the external magnetic field are explained by the high surface recombination velocity at the interface. After laser irradiation of this structure the rectification factor increase s with an increase in irradiation intensity, starting from I = 0.2 MW/cm(2) . This phenomenon is explained by the rise of the potential barrier at the interface owing to the generation of LD centres in the temperature gradient . The influence of LR on the luminescence spectra has shown that at a thres hold intensity of LR I = 0.2 MW/cm(2) generation of donor type A-centres be gins. (C) 2001 Elsevier Science Ltd. All rights reserved.