Recently, CdZnTe (CZT) detectors have emerged as the dominant semiconductor room temperature radiation detectors. However, their wide deployment is hampered by the low availability of high-quality CZT crystals. Among which, material’s inhomogeneity in bulk grown CZT crystals, especially due to the structure imperfections, still creates a ‘bottle-neck’ in state of the art wafer assessment and screening. It has been widely reported that the presence of Te-rich secondary phase particles (inclusions) in CZT crystals tends to affect the structural uniformity, in turn dominates the properties of spectrometer-grade CZT crystals. Therefore, Te inclusions in CZT crystals and the effects of Te inclusions on the energy resolution of CZT detectors have been studied numerically and experimentally for the last years. However, more and more evidences suggest that not only Te inlusions, but also their induced extended defects would influence CZT detectors’ performance.

In this work, the generation and coupling effects mechanisms of Te inclusions and their induced defects are discussed. Employing surface-etching techniques, Te inclusions on (111)_Cd, and (111)_Te surfaces of CZT crystals were observed using a field emission scanning electron microscope (FE-SEM) and a cathodoluminescence (CL) microscopy. The coupling effects between Te inclusion and the induced dislocations were discussed by analyzing the dislocations rosette surrounding Te inclusions. Finally, a focused ion beam/scanning electron microscope (FIB/SEM) was used to prepare thin sections for transmission electron microscopy (TEM) studies. The phase structure and lattice deformation of local areas were identified by HRTEM. It was suggested that the dislocation enriched region was proportional to the volume of the originating Te inclusion.

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