Role of selenium addition to CdZnTe matrix for room-temperature radiation detector applications
Role of selenium addition to CdZnTe matrix for room-temperature radiation detector applications
复制标题
DOI：
10.1038/s41598-018-38188-w
复制
发表时间：
2019-02-07
影响因子：
4.6
通讯作者：
James, R. B.
中科院分区：
文献类型：
--
作者：
Roy, U. N.;Camarda, G. S.;James, R. B.
碲化锌镉(CZT)具有理想的禁带宽度、高密度和高电子迁移率寿命，是目前最好的室温化合物半导体X射线和伽马射线探测器材料。然而，由于其固有的较差的热物性和锌的单位分凝系数以上，这种材料在大容量CZT探测器中的广泛应用仍然受到较高的生产成本的限制。高质量材料成品率低的根本原因是CZT存在三大有害缺陷：成分不均匀、位错壁/亚晶界网络密度高和Te夹杂物/析出物浓度高。为了缓解所有这些缺点，我们首次报道了在CZT基质中添加硒的影响。Se的加入有效地阻止了亚晶界及其网络的形成，显著减少了锌的偏析，改善了成分的均匀性，使Te夹杂物/析出物的浓度大大降低。本文报道了用移动加热法(THM)生长新的四元晶体Cd_(1-x)Zn_xTe_(1-y)Sey(CZTS)。根据其成分均一性，我们已经证明了其产量要高得多，具有显著较低的亚晶界及其网络，以及较低的Te夹杂物/沉淀物浓度。
Because of its ideal band gap, high density and high electron mobility-lifetime product, cadmium zinc telluride (CdZnTe or CZT) is currently the best room-temperature compound-semiconductor X- and gamma-ray detector material. However, because of its innate poor thermo-physical properties and above unity segregation coefficient for Zn, the wide spread deployment of this material in large-volume CZT detectors is still limited by the high production cost. The underlying reason for the low yield of high-quality material is that CZT suffers from three major detrimental defects: compositional inhomogeneity, high concentrations of dislocation walls/sub-grain boundary networks and high concentrations of Te inclusions/precipitates. To mitigate all these disadvantages, we report for the first time the effects of the addition of selenium to the CZT matrix. The addition of Se was found to be very effective in arresting the formation of sub-grain boundaries and its networks, significantly reducing Zn segregation, improving compositional homogeneity and resulting in much lower concentrations of Te inclusions/precipitates. Growth of the new quaternary crystal Cd1-xZnxTe1-ySey (CZTS) by the Traveling Heater Method (THM) is reported in this paper. We have demonstrated the production of much higher yield according to its compositional homogeneity, with substantially lower sub-grain boundaries and their network, and a lower concentration of Te inclusions/precipitates.