Levels of structural modification of noncrystalline semiconductors and limits of their applicability

The method for the structural modification of noncrystalline semiconductors consists in controlling the properties of these materials by changing thei r structure at a fixed chemical composition. It is shown that there exist a t least four levels of structural modification distinguished by changes in the material structure: the levels of short- and medium-range order, morpho logy, and the defect subsystem. Each level of structural modification affec ts a certain group of properties. The possibility and efficiency of changin g the structure at different levels of the above classification is analyzed for covalent semiconducting compounds of elements belonging to Groups IV-V I of the periodic table and some systems on their basis. Based on this anal ysis. the applicability Limits of various levels of structural modification are determined. (C) 2001 MAIK "Nauka/Interperiodica".