Local structure of semiconductor glasses in the germanium-sulfur and germanium-selenium systems

Abstract

129Te(129I) and 119Sn Mossbauer investigations have revealed that the structure of Ge100 − xSx and Ge100 − xSex glasses enriched in the chalcogen (x ≥ 0.66) is built up of structural units containing twofold-coordinated chalcogen (X) atoms in chains of the Open image in new window and Open image in new window types, whereas germanium atoms in these glasses have the oxidation state of only +4 and are fourfold-coordinated so that the local environment of the germanium atoms includes only chalcogen atoms. The structure of the glasses depleted in the chalcogen consists of structural units containing twofold-coordinated chalcogen atoms in chains of the Open image in new window type and threefold-coordinated chalcogen atoms in chains of the Open image in new window type, whereas germanium in these glasses is stabilized both in the oxidation state of +4 and the fourfold-coordinated state and in the oxidation state of +2 and the threefold-coordinated state so that the local environment of the germanium atoms includes only chalcogen atoms.