The Electronic Structure of a D^- Centre in Many-Valley Semiconductors

Abstract

The binding energies of a D - ion in the stress free and high stress cases are calculated with use of the Chandrasekhar type variational function. In the approximation of neglecting the valley-orbit interaction, the ionization energy of an electron from a D - ground state to a conduction band in the intravalley electron configuration corresponds to the D - binding energy in the high stress case while that in the intervalley configuration to the binding energy in the stress free case. In the former case the calculated value is the half of the observed one while in the latter case the calculated value is in fair agreement with the observed one. The energy difference between two cases is mainly due to the difference between the intra-and inter-valley Coulomb interactions.