Lateral Diffusion in Ag–Se Thin-Film Couples

Abstract

A study has been made of the diffusion of Ag along thin evaporated Se films using optical and transmission electron microscopy. The effect on the growth rate of varying both the Ag and Se film thicknesses and the temperature has been studied. Thin‐film diffusion rates were considerably faster than in bulk diffusion couples, indicating some short‐circuit diffusion mechanism. An important result of the investigation was the demonstration of a critical thickness ratio of Ag to Se which had to be exceeded in order for diffusion to occur. This critical ratio depended only on the stoichiometry of the Ag₂Se phase formed during diffusion.