Physical foundations of metastable impurity center reconstruction in semiconductors

The manner in which the electronic structure and chemical bonding of a perf ect crystal change upon doping and vary with the charge state of a defect i s analyzed. The obtained results serve as a basis for proposing a general p attern of reconstruction of metastable impurity centers, of both donor and acceptor types, in various semiconductors: "classical" III-V and II-VI semi conductor compounds, mostly ionic CdF2 crystal, and narrow-gap IV-VI compou nds. Reasons are revealed for center reconstruction; general tendencies of the process and the specificity of their manifestation in some classes of c rystals and types of impurity centers are established. (C) 2001 MAIK "Nauka /Interperiodica".