Photoemission studies of As_xSe_100−x (x: 0, 50, 100) films prepared by pulsed-laser deposition—the effect of annealing

Annealing-induced structural changes in amorphous films As_xSe_100−x (x: 0, 50, 100) prepared by pulsed laser deposition (PLD) on Si substrates were studied by x-ray and ultraviolet photoelectron spectroscopies (XPS, UPS). For x = 50, the analysis of the XPS As 3d peak revealed three distinct local environments in which the As atoms participate in the as-prepared films. The combination of photoemission and work function measurements showed that annealing close to the glass transition temperature induces atomic rearrangements towards the formation of a more homogenous surface composition as well as to a more energetically favoured film structure, by cleavage of the weaker As–As and Se–Se bonds towards the formation of As–Se ones analogously to As–S system films.