CZT detectors fabricated from horizontal and vertical Bridgman-grown crystals

Characterizations of Cd1−xZnxTe (0.04<x<0.24) detector crystals grown by vertical high-pressure Bridgman (VHPB), vertical ambient pressure Bridgman (VB), horizontal ambient pressure Bridgman (HB) and vapor-grown crystals obtained from various sources were compared. The following methods were applied: (1) Triaxial double crystal X-ray diffraction (TADXRD) to determine the crystal homogeneity and Zn content. (2) Sensitivity to radiation from high-flux X-rays to investigate detector efficiency and contacts. (3) Laser-induced transient charge technique (TCT) for measuring the carrier lifetimes. (4) Thermoelectric voltage spectroscopy (TEVS) and thermal-stimulated current spectroscopy, (TSC) to study the carrier traps. (5) IR imaging to characterize macroscopic crystalline defects. We compared cadmium zinc telluride crystals grown by different methods in order to understand better the nature of defects, which influence their nuclear spectroscopic response, and how the defects are affected by the growth technique.