Nano-scale annealing-induced structural changes in As-rich pulsed laser deposited AsxSe100−x films studied by XPS

Amorphous chalcogenide films from the binary system AsxSe100−x (x: 0, 40, 50, 60, 70, 100) were prepared by pulsed laser deposition on Si substrates. Annealing-induced changes at the electronic environment of the constituent structural units of the films were investigated using X-ray photoelectron spectroscopy. The analysis has revealed three distinct local environments in which the As atoms participate. The surface composition of the films with x = 50, 60 underwent significant changes after annealing whilst the stoichiometric and the richer in arsenic composition exhibited no detectable changes. The results are discussed in the context of existing structural models for amorphous arsenic selenides.