Investigating the influence of CdZnTe and HgCdTe material quality on detector image performance

High-quality tellurium zinc cadmium (CZT) crystal materials and tellurium cadmium mercury (MCT) epitaxial materials are the key materials for the preparation of high-performance MCT-cooled detectors. Studying the relationship between material defects and device imaging is essential for improving the material quality and device performance. In this work, we summarize the defects of the CZT single crystal and the surface defects of the MCT film. Furthermore, we demonstrate the effect of CZT and MCT material defects and lattice matching on the imaging performance of the chips, and summarize the material quality improvement and the standard control methods. Through processes such as heat treatment, the size of the inclusions is controlled to be less than 20 μm and the density is less than 20 cm −2 . A focal plane array (FPA) with good uniformity imaging (NETD 14.9 mK, defective pixel rate 0.03%) can be obtained by improving the material preparation level and formulating suitable material selection standards. Based on the continuous improvement of yield of FPA preparation process, MCT detectors can be fabricated in batches based on the optimized material quality.