CZT X-ray detectors obtained by the boron encapsulated vertical Bridgman method

Recently, some of the authors showed that it is possible to grow CZT crystals by the boron oxide encapsulated vertical Bridgman method. The most important feature of the technique is that the crystal, during the growth, is fully encapsulated by a thin layer of liquid boron oxide, so that the crystal-crucible contact is prevented. The stress of the crucible to the crystal is strongly reduced also during the cooling, because the boron oxide layer is molten down to about 500°C. A number of detectors have been prepared out of these crystals. The transport properties (μτ product) have been studied by photoconductivity measurements as well as by determining the response to hard X-ray irradiation. The transport properties have been studied as a function of the indium content and of the position of the wafer which the detector was cut out.