室温核辐射探测器用TlBr单晶生长机理及器件技术研究

项目名称： 室温核辐射探测器用TlBr单晶生长机理及器件技术研究

项目编号： No.61076074

项目类型： 面上项目

立项/批准年度： 2011

项目学科： 建筑科学

项目作者： 龚树萍

作者单位： 华中科技大学

项目金额： 16万元

中文摘要： 项目以提高TlBr单晶的质量为基础，系统地研究了垂直梯度凝固法的工艺参数对TlBr单晶各性能参数的影响规律。针对TlBr单晶的垂直梯度凝固法生长中出现的一些独特现象，结合晶体生长动力学等相关理论进行了解释。以TlNO3和HBr为前驱体合成具有不同Tl/Br原子比的TlBr(1+x)Br过量粉体，研究Br元素过量比晶体的红外透过率、禁带宽度、电阻率等质量参数的影响，并给出了最佳的Br过量比。对粉体中Br元素的最佳补偿可将TlBr晶体的红外透过率及电阻率分别提高40%及71%。通过对温度梯度及生长速率的优化，晶体红外透过率平均值可达68.1%，电阻率为3.47×11Ωm，且晶体以单核模式生长。TlBr探测器元件对241Am 59.5keV射线的最好的能量分辨率为11.8%，较上一基金中的38%的能量分辨率有极大改进。同时晶片还对137Cs 662keV高能X射线表现出了明显的响应，能量分辨率为9.0%。

中文关键词： 室温核辐射探测器；TlBr；单晶生长

英文摘要： Aiming at the improvement of the TlBr crystal quality, systemic research on relationship between the technical parameters of EDG method and the TlBr crystal quality have been done in this program. To explain the phenomena exhibited in the EDG growth of the TlBr crystal, related theories in crystal growth dynamics have been combined. TlBr powders with different Tl/Br atom ratio have been synthesized from TlNO3 and HBr. The influences of the Br excessive ratio on the crystal’ IR transmittance, band gap energy, resistance as well as other crystal qualities have been analyzed and the best Br excessive ratio is given. By Br element compensation the IR transmittance and the resistance of the TlBr crystal can be elevated by 40% and 71%, respectively. By optimization of the temperature gradient and growth rate, the IR transmittance of the TlBr crystal can reach 68.1% and its resistance reaches 3.47×11Ωm, meanwhile, the crystal grows in a single crystal nucleus. Best detector performance to the 241Am 59.5keV radiation is 11.8%, which is far beyond that in last program (38%). The wafer also exhibits obvious response to the 137Cs 662keV high energy radiation, whose energy resolution is 9.9%.

英文关键词： Room temperature radiation detector; TlBr; Single crystal growth