Kinetics of the thermally and photoinduced solid state reaction of Ag with As33S67 films

Abstract

The kinetics of the solid state chemical reaction of silver with amorphous As33S67 films in a conventional sandwich structure was measured by optically monitoring the change in thickness of the undoped chalcogenide. For the thermally stimulated process, the kinetics data indicate a two-stage process, with the second stage having a sublinear time dependence. The effect of broadband illumination is to reduce the activation energy by approximately one order of magnitude, but the photoinduced process still has two identifiable stages. In the case of the photostimulated process, rate coefficients and activation energies have been measured and the composition and structure of the reaction products have been determined by Rutherford backscattering spectroscopy (RBS). The RBS spectra obtained at different stages of the photoinduced reaction process show a step-like form for the Ag concentration profile during the course of the reaction and indicated a homogeneous distribution of Ag in the final reaction products, the Ag concentration being 19.5 at. %.