Characterization of Stress in Thallium Bromide Devices
Characterization of Stress in Thallium Bromide Devices
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DOI：
10.1109/tns.2015.2400396
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发表时间：
2015-03
影响因子：
1.8
通讯作者：
A. Datta;S. Motakef
中科院分区：
文献类型：
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作者：
A. Datta;S. Motakef
溴化铊（TlBr）是一种宽禁带的化合物半导体，具有较高的阻挡伽马射线的能力和良好的物理性能。几种表面改性技术已经被证明可以提高TlBr器件在室温下的寿命。然而，TlBr探测器的性能缺乏再现性（即使在-20°C的低离子导电性下）表明存在未探索的体现象。TlBr晶体中由于各种内在（例如晶界和位错网络）以及外部因素（如热、机械和电负载）引起的应力解释了探测器到探测器的变化。应用光弹性和光电技术可视化和定性地将器件性能与应力联系起来。应力模式随环境温度的变化而变化。利用波克尔斯效应首次观察到TlBr探测器中电场随时间的波动。
Thallium bromide (TlBr) is a wide bandgap, compound semiconductor with high gamma-ray stopping power and promising physical properties. Several surface modification techniques have been demonstrated to increase the lifetime of TlBr devices at room temperature. However, absence of reproducibility in the performance of TlBr detectors (even with low ionic conduction at -20°C) suggests presence of unexplored bulk phenomena. Stress in the TlBr crystal due to various intrinsic (e.g. grain boundaries and dislocations networks) in conjunction with external factors such as thermal, mechanical, and electrical loadings explains detector-to-detector variations. Photoelasticity and opto-electrical techniques were applied to visualize and qualitatively correlate the device performance with stress. Changes in stress patterns with variations in ambient temperature were clearly demonstrated. Electric field fluctuations in TlBr detectors with time were for the first time observed using the Pockels effect.