中国物理B ›› 2018, Vol. 27 ›› Issue (11): 117202-117202.doi: 10.1088/1674-1056/27/11/117202

所属专题: SPECIAL TOPIC — 80th Anniversary of Northwestern Polytechnical University (NPU)

• SPECIAL TOPIC—Recent advances in thermoelectric materials and devices • 上一篇    下一篇

Twin boundary dominated electric field distribution in CdZnTe detectors

Jiangpeng Dong(董江鹏), Wanqi Jie(介万奇), Jingyi Yu(余竞一), Rongrong Guo(郭榕榕), Christian Teichert, Kevin-P Gradwohl, Bin-Bin Zhang(张滨滨), Xiangxiang Luo(罗翔祥), Shouzhi Xi(席守智), Yadong Xu(徐亚东)   

  1. 1 State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China;
    2 Key Laboratory of Radiation Detection Materials and Devices, Northwestern Polytechnical University, Xi'an 710072, China;
    3 School of Optoeletronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China;
    4 Institute of Physics, Montanuniversitaet Leoben, Leoben 8700, Austria
  • 收稿日期:2018-07-14 修回日期:2018-08-16 出版日期:2018-11-05 发布日期:2018-11-05
  • 通讯作者: Yadong Xu E-mail:xyd220@nwpu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. U1631116 and 51702271), the National Key Research and Development Program of China (Grant No. 2016YFE0115200), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2017KW-029), Austrian Academic Exchange Service (ÖD-WTZ) through project CN 02/2016, the Fundamental Research Funds for the Central Universities of China (Grant Nos. 3102017zy057 and 3102018jcc036), and the Young and Middle-aged Teachers Education and Scientific Research Foundation of Fujian Province, China (Grant No. JAT170407).

Twin boundary dominated electric field distribution in CdZnTe detectors

Jiangpeng Dong(董江鹏)1,2, Wanqi Jie(介万奇)1,2, Jingyi Yu(余竞一)2, Rongrong Guo(郭榕榕)3, Christian Teichert4, Kevin-P Gradwohl4, Bin-Bin Zhang(张滨滨)2, Xiangxiang Luo(罗翔祥)2, Shouzhi Xi(席守智)2, Yadong Xu(徐亚东)1,2   

  1. 1 State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China;
    2 Key Laboratory of Radiation Detection Materials and Devices, Northwestern Polytechnical University, Xi'an 710072, China;
    3 School of Optoeletronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China;
    4 Institute of Physics, Montanuniversitaet Leoben, Leoben 8700, Austria
  • Received:2018-07-14 Revised:2018-08-16 Online:2018-11-05 Published:2018-11-05
  • Contact: Yadong Xu E-mail:xyd220@nwpu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. U1631116 and 51702271), the National Key Research and Development Program of China (Grant No. 2016YFE0115200), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2017KW-029), Austrian Academic Exchange Service (ÖD-WTZ) through project CN 02/2016, the Fundamental Research Funds for the Central Universities of China (Grant Nos. 3102017zy057 and 3102018jcc036), and the Young and Middle-aged Teachers Education and Scientific Research Foundation of Fujian Province, China (Grant No. JAT170407).

摘要:

The performance of CdZnTe X/γ-ray detectors is strongly affected by the electric field distribution in terms of charge transport and charge collection. Factors which determine the electric field distribution are not only electric contact, but also intrinsic defects, especially grown-in twin boundaries. Here, the electric field distribution around twin boundaries is investigated in a CdZnTe bicrystal detector with a {111}-{111} twin plane using the Pockels electro-optic effect. The results of laser beam induced current pulses are also obtained by the transient current technique, and we discuss the influence of the twin boundary on the electric field evolution. These studies reveal a significant distortion of the electric field, which is attributed to the buildup of space charges at twin boundaries. Also, the position of these space charge regions depends on the polarity of the detector bias. An energy band model based on the formation of an n-n+-n junction across the twin boundary has been established to explain the observed results.

关键词: electric field distribution, CdZnTe, twin boundary, Pockels effect

Abstract:

The performance of CdZnTe X/γ-ray detectors is strongly affected by the electric field distribution in terms of charge transport and charge collection. Factors which determine the electric field distribution are not only electric contact, but also intrinsic defects, especially grown-in twin boundaries. Here, the electric field distribution around twin boundaries is investigated in a CdZnTe bicrystal detector with a {111}-{111} twin plane using the Pockels electro-optic effect. The results of laser beam induced current pulses are also obtained by the transient current technique, and we discuss the influence of the twin boundary on the electric field evolution. These studies reveal a significant distortion of the electric field, which is attributed to the buildup of space charges at twin boundaries. Also, the position of these space charge regions depends on the polarity of the detector bias. An energy band model based on the formation of an n-n+-n junction across the twin boundary has been established to explain the observed results.

Key words: electric field distribution, CdZnTe, twin boundary, Pockels effect

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

  • 72.80.Ey
61.72.Mm (Grain and twin boundaries) 07.85.Fv (X- and γ-ray sources, mirrors, gratings, and detectors)