Charge carrier drift mobility and mean lifetime evaluation on high resistivity MGHB Cd1xZnTe crystal growth

Cdl1-xZnxTe has attracted much attention as a new material for high-resolution room-temperature γ-ray detectors. CdZnTe (CZT) is a promising material in a variety of fields, including nuclear medicate and astronomy. A CZT detector can operate at room temperature due to its large bandgap, and being free of polarization effects found in CdTe. It has been reported that the addition of Zn led to an improvement of crystalline quality and to decrease in dark current compared to CdTe. The crystal growth process must be refitted to reduce cost a)td increase the yield of large volume spectroscopic crystals. High Pressure Bridgman (HPB) grown crystals have high resistivities about 1011 Ω-cm and the benefit of low structural defects. Yet the yield of HPB is low. It has been reported that a version of modified-horizontal-Bridgman the Moving Gradient Horizontal Bridgman (MGHB) technique was used to grow the CZT crystals by IMARAD. The MGHB can produce low defect crystals of larger dimensions. It is well established that the main challenge in growing high resistivity CZT materials is to improve the charge carrier transport properties. The CZT semiconductor spectrometer charge carriers' most important transport properties are the d?ifi mobility and the mean lifetime. The electrons drift mobility (μe) and mean lifetime (τe) can be obtained by irradiating well collimated γ rays through the crystal cross section negative contact (and d using the Time -Of Flight (TOF) technique. Similarly in principle, irradiation of well-collimated γ-rays beam through the crystal positive contact can yield the hole drift mobility (μh) and mean lifetime (τh). However, in practice the signal produced .from irradiating the positive contact does not yield measurable signals Cue to the low μhτh product. This work presents MGHB CZT evaluated crystal charge carrier transport properties. Evaluation of the hole transport properties by spectrum measurement together with Monte-Carlo simulation we done. Higher CZT crystal hole transport properties then reported in the literature were found