Structural organization of As-rich selenide glasses

•Structural properties of As-rich As–Se glasses are studied by XPS.•Nearest surroundings for each constituting element are identified and quantified.•Significant deviations from “chain-crossing” model are found for x=50 and 55 compositions.

The structure of bulk AsxSe100−x (40≤x≤55) glasses, prepared by conventional melt-quenching method, is investigated using high-resolution XPS. The moieties of constituting structural fragments are evaluated and compared to those determined from the “chain-crossing” model. Significant deviations from this model are observed for x=50 and x=55 compositions. In glasses with concentration of As higher than 50 at% the tendency to As segregation and formation of Se–Se bonds is demonstrated. Deviations from “8-N” rule are not found in the structure of the investigated As-rich selenide glasses.