Analysis of Cd1-xZnxTe microstructure

摘要

The microstructure and chemical inhomogeneities of commercially available Cd$-1-x$/Zn$-x$/Te (CZT) have been evaluated using electron microscopy and microanalytical techniques. Since imperfections, such as inclusions, cracks and extended crystallographic defects are known to affect the performance of CZT gamma-ray spectrometers, understanding the nature and origins of such imperfections is vital to the improvement of device performance. CZT that is grown using a high-pressure Bridgeman method has a polycrystalline microstructure containing numerous grain boundaries, twins and inclusions. In this study, scanning electron microscopy and x- ray energy-dispersive spectroscopy were used to analyze inclusions and cracks inside CZT material. Such analysis found regions of material rich in C, O, Si, Zn, and Te. Transmission electron microscopy revealed small subgrains and thin platelets of a second phase material located inside the large- grain CZT matrix. Details of these microstructural features and their possible origins are discussed.