CZT detectors fabricated from horizontal and vertical Bridgman-grown crystals

Characterizations of Cd1-xZnxTe (0.04 < x < 0.24) detector crystals grown b y vertical high-pressure Bridgman (VHPB), vertical ambient pressure Bridgma n (VB), horizontal ambient pressure Bridgman (HB) and vapor-grown crystals obtained from various sources were compared. The following methods were app lied: (1)Triaxial double crystal X-ray diffraction (TADXRD) to determine th e crystal homogeneity and Zn content. (2) Sensitivity to radiation from hig h-flux X-rays to investigate detector efficiency and contacts. (3) Laser-in duced transient charge technique (TCT) for measuring the carrier lifetimes. (4) Thermoelectric voltage spectroscopy (TEVS) and thermal-stimulated curr ent spectroscopy, (TSC) to study the carrier traps. (5) IR imaging to chara cterize macroscopic crystalline defects. We compared cadmium zinc telluride crystals grown by different methods in order to understand better the natu re of defects, which influence their nuclear spectroscopic response, and ho w the defects are affected by the growth technique. (C) 2001 Elsevier Scien ce B.V. All rights reserved.