Positron Annihilation Study of Doping Effect in Chalcogenide Glassy Semiconductors

The effect of metal admixtures on the structure and imperfections of chalcogenide glassy semiconductors is investigated for Ga admixture in GeSe4 glass. Information is obtained by the positron annihilation technique. A microcrystalline phase in glass under doping at low admixture concentrations (about 0.01 at %) is indicated. The characteristic sizes of microinclusions and the amount of admixture atoms they contain are estimated. New aspects of the earlier interpretation (on the basis of the "induction effect") of the doping effect on electrophysical properties of glass are found.