ELECTRON-STRUCTURE OF AN IMPURITY AT A DISLOCATION

A quantitative theory of the electron structure of group V impurities in covalent semiconductors is developed. It is shown that the usual assumption that an impurity is located on the axis of a dislocation is not supported by ESR data. A new model is proposed in which an impurity atom is located at a distance of the order of the lattice constant from the axis of a dislocation. The new model is used to calculate the donor, acceptor, and resonant states. The position of resonant state is shown to agree well with the results of DLTS experiments on phosphorus atoms at dislocations in silicon.