硒族纳米晶辐射探测材料研究

The selenide nanocrystal radiation detector materials will be used for the new-type nuclear detection technology in the future due to their less signal loss, high detection efficiency, and lost cost, which will make the semiconductor radiation detectors used popular in the industry and life. In this proposal, the first principal will be used to simulate the electron structure, carrier concentration and mobility, and other important parameters of the two or three element selenium compounds. The ab initio molecular dynamic method will be used to simulate the crystal structure, defect evolution and the electrical properties under radiation. The radiation detection performance will be predicted and the selenium compounds with good properties will be obtained. Based on the simulated results, the corresponding selenide nanocrystal film will be prepared and the thermal annealing will be conducted to improve the electrical properties of the materials. Finally, the radiation detectors based on the good selenide nanocrystal film will be fabricated and the detection experiments on the alpha particles and gamma rays will be conducted. The electrical response to radiation source will be analyzed and their energy resolution and other important parameters will be obtained. According to the radiation detection results, the nanocrystal film will be improved to obtain the film materials with good detection performance and their preparation technique to provide reference for the radiation detection engineering.

硒族纳米晶辐射探测材料具有信号损耗少、探测效率高和低成本等优势，是未来新型核探测技术的发展方向，增加了半导体辐射探测器普及到生产、生活各个领域的可能性。本项目拟采用第一性原理模拟计算不同元素组成的二元/三元硒族化合物体系的电子结构、载流子浓度和迁移率等关键参数，采用从头算分子动力学方法模拟硒族化合物在辐射环境下的晶体结构、缺陷演变及其对材料电学性质的影响，预测硒族纳米晶材料的辐射探测性能，给出优化体系。根据理论优化结果，制备相应的纳米薄膜材料，并结合热退火改善探测材料的电学特性，最后基于优质的硒族纳米晶薄膜制作辐射探测器件，并开展α粒子和γ射线探测实验，研究器件的电学响应特性，获得能量分辨率等重要参数。依据辐射探测结果，改进纳米薄膜的制备方法，最终获得辐射探测性能优良的纳米薄膜体系和相应的制备工艺，为工程应用提供参考。

理论计算了Ag掺杂对CdSe纳米晶的结构、电子和光学性质的影响，发现Ag掺杂原子的位置和数量是改变电子结构的关键因素；Ag掺杂可以大大增强CdSe对紫外-可见区的光的吸收，并将CdSe量子点的吸收边缘扩展到红外区。计算了Cu掺杂剂的位置对CdSe纳米晶体电子结构的影响。对CdSe、CdTe基纳米线阵列的制备、微结构及光辐射的探测性能做了实验研究，发现CdSe-CdTe基结构对光辐射具有较宽的光谱响应范围；利用钠辅助外延法生长了二维超薄Sb2Se3纳米片样品，二维超薄Sb2Se3纳米片具有宽的光谱响应区间，良好的光辐射探测能力；对镍基硒化物、过渡金属掺杂镍基硒化物的制备、微结构及电学性质做了实验研究，可以成功获得镍基硒化物和过渡金属掺杂的硒化镍，过渡金属掺杂可以有效提升硒化镍的电化学性质。研究了γ射线辐照对MoS2纳米材料的微观结构和导电性能的影响。