Local Structure of Semiconductor Glasses in the Germanium-Sulfur and Germanium-Selenium Systems

摘要

~(129)Te(~(129)I) and ~(119)Sn Mossbauer investigations have revealed that the structure of G_(100-x)S_x and Ge_(100-x)Se_x glasses enriched in the chalcogen (x ≥ 0.66) is built up of structural units containing twofold-coordinated chalcogen (X) atoms in chains of the -Ge-X-Ge- and -Ge-X-X-Ge- 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 -Ge-X-d e- type and threefold-coordinated chalcogen atoms in chains of the -Ge-X-Ge- 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.