Microstructure and imperfections of glassy and glass-ceramic telluride semiconductors on the basis of positron annihilation

The microstructures of glassy and glass-ceramic telluride semiconductors are studied by the positron annihilation technique. The validity of some structural models for such materials is analysed. An identification technique of defects (positron trapping centers) in these semiconductors is proposed. Quantitative estimations of defect concentrations are made. Additional evidence for the co-existence of two phases in the Si-Te system over certain ranges of Te concentrations is presented. The characteristic sizes of microcrystalline inclusions in Ge-Te and Si-Te glass-ceramics are estimated. (author)