中国物理B ›› 2021, Vol. 30 ›› Issue (3): 36101-.doi: 10.1088/1674-1056/abc67e

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  • 收稿日期:2020-08-06 修回日期:2020-10-26 接受日期:2020-10-31 出版日期:2021-02-22 发布日期:2021-03-05

Influence of sub-bandgap illumination on space charge distribution in CdZnTe detector

Rongrong Guo(郭榕榕)†, Jinhai Lin(林金海), Lili Liu(刘莉莉), Shiwei Li(李世韦), Chen Wang(王尘), Feibin Xiong(熊飞兵), and Haijun Lin(林海军)   

  1. 1 Fujian Provincial Key Laboratory of Optoelectronic Technology and Devices, Xiamen University of Technology, Xiamen 361024, China
  • Received:2020-08-06 Revised:2020-10-26 Accepted:2020-10-31 Online:2021-02-22 Published:2021-03-05
  • Contact: Corresponding author. E-mail: 2016000050@xmut.edu.cn
  • Supported by:
    Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 51702271 and 61904155) and the Natural Science Foundation of Fujian Province, China (Grant No. 2020J05239).

Abstract: \baselineskip=12.5pt plus.2pt minus.2pt The space charge accumulation in CdZnTe crystals seriously affects the performance of high-flux pulse detectors. The influence of sub-bandgap illumination on the space charge distribution and device performance in CdZnTe crystals were studied theoretically by Silvaco TCAD software simulation. The sub-bandgap illumination with a wavelength of 890 nm and intensity of 8× 10 -8 W/cm2 were used in the simulation to explore the space charge distribution and internal electric field distribution in CdZnTe crystals. The simulation results show that the deep level occupation faction is manipulated by the sub-bandgap illumination, thus space charge concentration can be reduced under the bias voltage of 500 V. A flat electric field distribution is obtained, which significantly improves the charge collection efficiency of the CdZnTe detector. Meanwhile, premised on the high resistivity of CdZnTe crystal, the space charge concentration in the crystal can be further reduced with the wavelength of 850 nm and intensity of 1× 10 -7 W/cm2 illumination. The electric field distribution is flatter and the carrier collection efficiency of the device can be improved more effectively.

Key words: CdZnTe detector, sub-bandgap illumination, space charge, charge collection efficiency

中图分类号:  (III-V and II-VI semiconductors)

  • 61.72.uj
61.72.-y (Defects and impurities in crystals; microstructure) 85.25.Oj (Superconducting optical, X-ray, and γ-ray detectors (SIS, NIS, transition edge)) 78.56.Cd (Photocarrier radiometry)