New approaches in order to enlarge the grain size of bulk CdZnTe (CZT) crystals

For the few decades, II-VI compound semiconductors are gaining attention because of its numerous applications in the field of detector technology, photovoltaic, nuclear medicine, astronomy etc. In the recent past, materials scientists focused their attention for the growth of CdTe/CdZnTe single crystals because it doesn’t require any specialized cooling and detects higher energy photos as in comparison with the existing Ge, Si and HgI₂ detectors. In the present study, we are going to discuss five main approaches in order to get good quality CZT crystal and we have successfully grown the CZT crystal by adopting these approaches. They are: i) oscillatory Bridgman technique previous to the growth process, ii) modifying the thermal environments in a Bridgman geometry using a Pt tube as a cold finger in order to reduce  the growth velocity iii) growth from the vapour phase using Bridgman geometry with a pyrolitic boron nitride (PBN) crucible to locate the feed material, and with a special temperature profile, iv) microgravity experiments in the FOTON M3 mission using magnetic field prior to the growth process and v) growth by a boron oxide encapsulation. The detailed discussions are given in the following sections.