Carrier-trapping-based imaging evaluation model and experiment of pixellated CdZnTe detector

被引：2

作者：

Li M. ^{[1
]}

Xiao S. ^{[1
]}

Wang X. ^{[1
]}

Cao Y. ^{[2
]}

Chen Y. ^{[2
]}

Nie L. ^{[1
]}

Zhang L. ^{[1
]}

机构：

[1] Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University

[2] Institute of Electronic Engineering, CAEP, Mianyang 621900

来源：

Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | 2011年 / 23卷 / 12期

关键词：

CdZnTe; Evaluation function; Radiation imaging detection; Semiconductor detector;

D O I：

10.3788/HPLPB20112312.3405

中图分类号：

学科分类号：

摘要：

A flexible induced charge model of CdZnTe pixellated detector is presented. This model takes into account the charge trapping effect in the detection process. The distribution of the trapped carriers in CdZnTe crystal is derived based on the continuity equations. In consequence, an evaluation model based on the presampling modulation transfer function (presampling MTF) is obtained. As shown through the numerical simulation, the detector imaging quality decreases obviously with the increase in incident photon energy. When the electron- and hole-mobility lifetime products are 0.5×10 -3 to 5.0×10 -3 cm 2/V and 2.0×10 -5 to 7.5×10 -5 cm 2/V, respectively, the model signal is almost due to the electron transport, and the hole transport contributes relatively little to the model signals. The carrier collection characteristics of the model correspond with the practical single polarity characteristics of the pixellated CdZnTe detector. Moreover, a 40 mm×40 mm CdZnTe imaging system has been established. The experimental data based on the obtained presampling MTF show that the simulation results are consistent with the experimental data well. The discrepancies between the simulated results and the experimental data are mainly attributed to the intrinsic deep level trapping centers, the poly-energetic X ray source that has been applied in the experiment and the practical pixel gap.

引用

页码：3405 / 3411

页数：6

共 20 条

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