Dopant content and thermal treatment of CdZnTe≪In≫: Effects on point-defect structures

Abstract

We measured, in the 873-1173 K temperature range, the temperature-and Cd vapor-pressure-dependences of the free electron density in single Cd1_xZnxTe<In> (0~x~0.1) crystals with different In contents. Increasing the cooling rate of the crystals and/or decreasing the well-defined Cd vapor pressure reduced the free-electron density. We interpreted and modelled these phenomena and the crystal's high-temperature electrical properties within the framework of Kroger's point-defect theory. Our experiments demonstrated the possibility of controlling the free-electron density in Cd1_xZnxTe<In> crystals by changing the cooling rate. We supplemented a point-defect structural study of these crystals by low-temperature (80-420 K) electrical measurements. These findings allowed us to identify the nature of the point defects responsible for free-carrier scattering, which is an important parameter influencing the fiT-product value in detector-grade material.

Enhancement of Resistivity of CdZnTe Crystal by Laser Radiation

“…1, curve 2, absorption by the free charge carrier decrease. This effect is explained by the decrease of V Cd concentration in the irradiated sample due to the recombination of V Cd and Cd interstitials (Cd i ) or In atoms [12]. It should be noted that, after irradiation by 3.6•10 4 laser pulses, the saturation of the transmission spectra was observed.…”

“…The increase of resistivity could be caused by the decrease of free charge carrier concentration in semiconductor due to the decrease of V Cd concentration. The compensation of V Cd by In decreases concentration of free electrons, as discussed in [12]. The degree of compensation is determined by the position of the Fermi level that is pinning near the mid-gap by the Te Cd deep donors.…”