Gamma- and X-ray detectors manufactured from [formula omitted] Te grown by a high pressure bridgman method

Abstract

Results of recent efforts in the growth of Cd 1−x Zn x Te crystals by a high pressure Bridgman (HPB) method and their use in gamma- and X-ray detector applications are presented. Evidence for crystals of relatively low defect content include etch pit densities of ≤ 10 4 cm −2 , double crystal rocking curve linewidths of 10–15″ and sharp, bright emission lines with excitonic features in low temperature photoluminescence measurements. Resistivities in excess of 10 11 ohm cm are achieved without impurity doping. The resulting low leakage currents lead to good energy resolution, <6% at 59.5 keV for example. The dependence of leakage current on temperature from 233 K to 373 K implies a Fermi level at mid-gap for x=0.2. The results of flash X-ray experiments indicate that the high current sensitivity, low leakage current and good temporal response of Cd 1−x Zn x Te detectors make them attractive candidates for applications involving short pulses at high dose rates.