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

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 ≤ × ≤ 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 Kröger’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 μτ -product value in detector-grade material.