Induced defects and structural changes resulting from the processing of CdTe and CdS thin film

The Rutherford backscattering (RBS) and thermoluminescence (TL) techniques are used to characterize thin films of CdTe and/or CdS deposited onto glass substrates for possible evolution of high-efficiency solar cells. The indu ced changes following annealing at 400 degrees C for 30 min and chemical pr ocessing in saturated CdCl2, solution, are investigated. Major structural c hanges are noted by the RES technique in a manner that is a function of the processing conditions. The TL data as obtained from the detected glow curv es indicate an impurity influence on both the deep and shallow charge traps and recombination centers. The TL glow curves also reveal the development of shallow defect states accompanied by a decrease in the amount of undesir able tunneling and interface recombination. The complementary TL and RES re sults are then discussed based on the model of lowering the interface defec ts density and the formation of an intermixed interface layer resulting fro m various impurity and him species interdiffusion (C) 2000 Elsevier Science B.V. All rights reserved.