<title>Deep impurity centers and intrinsic defects in new photorefractive CdHgTe:V crystals</title>

Abstract

The present paper is devoted to detailed investigation of the low-temperature optical and photoelectric properties of Cd 1-x Hg x Te:V (x 2+ and V 3+ (single and complex) impurity centers and singly charged complex acceptors. It was shown that the anisotropy of complex impurity centers is determined by the nature of the donor atom and its position in the crystal lattice. It should be noted that such crystals were grown for the first time by the Bridgman method. Transport measurements (T=300K) showed that the samples were highly compensated with a dark resistivity greater than 10 6 (Omega) $CTR cm. It was shown that the anisotropic V 2+ centers may be caused by formation of complex impurity (V 2+ Cd + X Te ) centers, where X are the accidental impurities of group VII atoms positioned at anionic sites. The appearance of rhombohedral V 2+ centers may be caused by the formation of the complex (V 2+ Cd + X Te ) centers whose axis is oriented in one of the direction. In the case of the tetragonal V 2+ centers the Z atoms are positioned at cationic sites in one of the equivalent directions. In the case of the Cd 1-x HG x Te:V crystals Z may be the Hg Atoms.