Deep Donor Levels in Semiconductors with Vacancies in the Anion Sublattice

Abstract

The impurity electron spectrum for undoped bulk crystals of n-type arsenides GaAs, InAs, CdSnAs2, CdGeAs2, and CdTe, ZnO has been studied by quantitative analysis of baric and temperature dependences of kinetic coefficients. The vacancies in the anion sublattice in these semiconductors have been found to be corresponding to deep donor centers for following reasons. Shallow intrinsic centers at hydrostatic pressure are dependent on their own band. In contrast, the energy of deep impurity centers at isotropic compression of crystal lattice is constant relative to absolute vacuum. The energy level locations relative to the conduction band edge and the pressure coefficients for energy spans between them and corresponding bottoms of conduction bands have been determined. Energy levels of deep donor centers shift into the depth of conduction band with a decrease of the band gap.