Zinc segregation in HPB grown nuclear detector grade Cd1−xZnxTe

CZT ingots have been grown by the high pressure Bridgman technique and their zinc concentration has been measured by X-ray fluorescence and PIXE on samples cut at different growth positions. The zinc concentration map has been traced for several wafers showing strong discrepancies along the explored area. The segregation coefficient has been calculated from the experimental data taking a directional freezing model. A very good fitting with experimental values is obtained especially for the PIXE results. Some detectors have been manufactured from the wafers and tested in nuclear detection. It is shown that pair creation energy is modified and that the saturation curve is modified from the head to the tail of the ingot.