The mechanism of defects effect on carrier transport by employing multi-wavelength sub-bandgap lights on CdZnTe crystal. (August 2020)

• Record Type: Journal Article
• Authors: Jin, Chengwei; Min, Jiahua; Liang, Xiaoyan; Zhang, Jijun; Shen, Yue; Chen, Jun; Dai, Ling-en; Liang, Shijin; Zhao, Shuhao; Wang, Linjun; Shi, Haozhi
• Is Part Of: Solid-state electronics. Volume 170(2020)
• Publication Date: 2020-08
• Subjects: CdZnTe -- Defects -- Sub-bandgap light -- Mobility-lifetime product; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2020.107823
• Languages: English
• ISSNs: 0038-1101

Abstract

Abstract: The effect of different point defects in CdZnTe (CZT) crystals on carrier transport performance were discussed. The energy level and concentration of the traps were determined by the photo-induced current transient spectroscopy (PICTS). By adding the infrared light illumination into the PICTS experiment, the effect of sub-bandgap light on defects was observed. Meanwhile, several DC photoconductive experiments were done under different wavelength lights were used to explore the effect of the different defects on carrier transport properties of CZT crystals. Furthermore, the energy spectrum test was used to investigate the effect of sub-bandgap light on the energy resolution of CZT detectors. The data results showed that sub-bandgap light could effectively change the ionization state of defects. The doubly ionized Te antisite (TeCd 2+ ) had the greatest effect on mobility-lifetime product(μτ) of electrons owing to its stronger ability of capturing electrons and energy level located around the midgap. While the secondary ionized Cd vacancy (VCd 2− ), as considered as a hole trap, had the greatest effect on μτ-product of holes. Consequently, choosing suitable infrared light can improve the detection performance of CZT crystal effectively.