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The local structure of amorphous As-Se films prepared by thermal evaporation in a vacuum and by RF ion-plasma sputtering, two techniques strongly differing in the conditions of substance vaporization and condensation of atoms on a substrate, was studied by Raman spectroscopy. It was found that the local structure of the films varies. A conclusion was drawn that the differences in local structure between the films are stipulated by the fact that the matrix of the films obtained by ion sputtering contains, along with the structural units common to films deposited by the two methods, other structural units.

Changes in the atomic structure and optical properties of amorphous films in the As-Se system upon annealing have been studied on films prepared by thermal evaporation in a vacuum and by RF ion-plasma sputtering. The annealing modifies the atomic structure of the films and shifts their optical absorption edge. Changes in the atomic structure mainly occur in the medium-range order. The most essential changes in the atomic structure and optical properties are observed for AsSe films. A correlation between changes in the medium-range order of the atomic structure and the optical gap of the films is established.

The atomic structure and electrical and optical properties of amorphous AsSe films prepared by thermal evaporation in a vacuum and by rf ion-plasma sputtering have been studied. The conductivity, activation energy of conductivity, optical gap, radii of the first and second coordination spheres, number of the nearest neighbours of arsenic and selenium atoms in the first coordination sphere and dimensions of the medium-range order domain in the atomic structure have been determined for the samples studied. Films prepared by different methods have dissimilar electrical and optical parameters and show differences in atomic structure, mainly related to the dimensions of the medium-range order domains. A conclusion is made that it is the medium-range order in the amorphous film atomic structure in the As-Se system that governs the electronic structure of amorphous films of the As-Se system.

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