Advances in the crystal growth and device fabrication technology of CdZnTe room temperature radiation detectors
Advances in the crystal growth and device fabrication technology of CdZnTe room temperature radiation detectors
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DOI：
10.1109/tns.2004.829391
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发表时间：
2004-06-01
影响因子：
1.8
通讯作者：
Szeles, C
中科院分区：
文献类型：
--
作者：
Szeles, C
CdZnTe室温x射线和伽玛射线探测器的性能是由控制载流子通过器件的材料和器件缺陷决定的。在这篇文章中，我们回顾了常见的体、界面和表面缺陷及其对电荷输运、电荷输运均匀性和器件性能的影响。我们注意到，在富te条件下生长的纯CdZnTe具有过量的cd空位和其他与te相关的天然缺陷，必须电补偿才能获得高电阻率材料。通过对各种补偿方案的分析表明，为了实现一种实用的补偿技术，必须引入给体掺杂元素的深层缺陷。讨论了载流子俘获的作用以及晶体尺寸增大对探测器性能的限制。根据典型的载流子寿命测量和载流子捕获截面的现有文献数据，我们估计CdZnTe探测器晶体中的剩余受体浓度远低于人们普遍认为的10(11)cm(-3)，而不是10(15)cm（-3）。还讨论了单晶结构缺陷的有害影响。我们还简要概述了CdZnTe晶体生长和器件制造技术的进展，旨在降低有害缺陷的浓度，提高CdZnTe探测器的性能。
The performance of CdZnTe room-temperature X-ray and gamma-ray detectors is determined by material and device defects that govern carrier transport trough the device. In this contribution, we review common bulk, interface, and surface defects and their effects on charge transport, charge transport uniformity, and device performance. We note that pure CdZnTe grown under Te-rich conditions has an excess of Cd-vacancies and other Te-related native defects and must be electrically compensated in order to obtain high resistivity material. Through the critical analysis of the various compensation schemes it is shown that deep level defects must be introduced with donor doping elements in order to achieve a practical compensation technique. The role of carrier trapping and limitations on detector performance with increasing crystal size are discussed. Based on typical measured carrier lifetimes and the available literature data on carrier capture cross sections, we estimate that the residual acceptor concentration in CdZnTe detector crystals is much lower than widely thought, about 10(11) cm(-3) instead of 10(15) cm(-3). The deleterious effects of structural defects within single crystals are also discussed. We also provide a brief overview of the progress in CdZnTe crystal growth and device fabrication technologies aiming at reducing the concentration of the detrimental defects and improving CdZnTe detector performance.