The effect of impurity and intrinsic defects on the energy structure and dynamic of electronic processes CdTe:V and Cd₁₋ₓHgₓTe:V crystals

Abstract

The electron trapping and detrapping processes in the semi-insulating CdTe:V crystals have been studied using a new time-resolved photoelectric spectroscopy technique. It has been shown that the electron processes in such crystals involving the impurity centers and intrinsic defects are fast and occur in the nanosecond range. The information on the nature and energy structure of the anisotropic impurity centers has been obtained. Two different photogeneration mechanisms of free electrons have been revealed: the direct photoionization of electrons from the ground impurity states and their self-ionization from the excited impurity states which are in resonance with the conduction band. It was found that the photosensitivity region for Cd₁₋ₓHgₓTe:V crystals (x = 0.018) at 300 K is in the range from 0.9 to 1.7 μm.