Size and distribution of Te inclusions in detector-grade CdZnTe ingots

To observe the Te inclusions distribution along the axial direction of CdZnTe ingots, batches of as-grown detector-grade CdZnTe crystals grown by vertical Bridgman method, were investigated using IR transmission imaging. However, there is not a rigorous regularity for the micron-scale Te inclusions distribution along the axial direction of CdZnTe ingots according to the measurements of the present investigation. The size and distribution variations of Te inclusions are attributed to the growth velocity, furnace temperature situation and morphological changes at the liquid-solid interface during crystal growth. Electron mobility lifetime products were discussed in conjunction with Te inclusions. However, no strict correlations are identified between the sizes and concentrations of Te inclusions and the γ-ray spectroscopy response. Extended defects in CdZnTe crystals, which are not visible via IR transmission imaging, potentially attribute to CdZnTe detectors performance degrades.