RUTHERFORD BACKSCATTERING AND KINETICS STUDY OF THE PHOTOINDUCED SOLID-STATE CHEMICAL-REACTION BETWEEN SILVER AND AMORPHOUS AS33S67 LAYERS

The kinetics of the photo-induced solid state chemical reaction of sil ver with a-As33S67 films in a conventional sandwich structure was meas ured by monitoring the change in thickness of the undoped chalcogenide using a modified computer-controlled technique. The kinetic data obta ined show that there are two stages in the photo-induced reaction proc ess. Rate coefficients and activation energies have been-measured and a comparison of the composition and structure of the reaction products detected by Rutherford backscattering spectroscopy (RES) has been mad e. The RES spectra obtained at different stages of the photo-induced r eaction process show a step-like form for the Ag concentration profile during the course of the reaction and indicate a homogeneous distribu tion of Ag in the final reaction products, the Ag concentration being 31 at.%. The step-like form of the Ag concentration profile is discuss ed in the framework of the G-c(Ag) diagram for the AE-As33S67 system. On the basis of the back scattering results a model is suggested which explains the kinetics of the photo-induced reaction.