Studies of short-range ordering in amorphous In–Se films by EXAFS

Abstract Amorphous In–Se films, containing 50, 60 and 66 at.% Se, prepared by vacuum evaporation, have been studied by extended absorption fine structure at the Se K-edge. A least-squares fitting procedure has been applied to analyse the measured spectra. The results indicate that for the In49Se51 amorphous film an In–Se contribution with the interatomic distance of 2.63 A and a threefold coordination of Se is involved in the nearest-neighbour coordination sphere. As the Se content is increased, the number of Se–In bonds is reduced and Se–Se bonds occur, preserving the total coordination number of Se. The relationship between the short-range order in the investigated films and the local atomic arrangements in corresponding crystalline polymorphs is discussed.