Cs_(3)Bi_(2)I_(9)晶体的生长及辐射探测性能

Growth and Radiation Detection Properties of Cs_(3)Bi_(2)I_(9) Crystal

采用布里奇曼法成功制备出大尺寸(Φ15 mm×50 mm)、高质量的全无机金属卤化物类钙钛矿Cs_(3)Bi_(2)I_(9)单晶。室温下,该晶体属于六方晶系,空间群为P63/mmc,密度为5.07 g/cm3,晶胞参数为a=b=0.840 nm,c=2.107 nm,熔点为632℃。采用粉末X射线衍射谱、紫外-可见-近红外漫反射光谱、I-V测试等表征该晶体的性质。制备Au/Cs_(3)Bi_(2)I_(9)/Au三明治型器件结构,采用飞行时间技术测试Cs_(3)Bi_(2)I_(9)晶体的载流子迁移率,得到Cs_(3)Bi_(2)I_(9)晶体的电子迁移率为4.33 cm^(2)·V^(-1)·s^(-1)。根据Hecht单载流子方程拟合得到Cs_(3)Bi_(2)I_(9)晶体的载流子迁移率寿命积(μτ)为8.21×10^(-5)cm^(2)·V^(-1),并且在500 V偏压下对α粒子的能量分辨率达到39%。

The large size and high quality inorganic metal halide perovskite Cs_(3)Bi_(2)I_(9)(Φ15 mm×50 mm)single crystal was successfully prepared by Bridgman method.The crystal belongs to the hexagonal system(P6_(3)/mmc)at room temperature and the parameters are a=b=0.840 nm,c=2.107 nm.The density of Cs_(3)Bi_(2)I_(9) is 5.07 g/cm^(3) and the melting point is 632℃.The crystal was characterized by powder X-ray diffraction,UV-Vis-NIR diffuse reflectance spectra and I-V test.The device structure of Au/Cs_(3)Bi_(2)I_(9)/Au is constructed to measure the carrier ability of Cs_(3)Bi_(2)I_(9) crystal by the time of flight(TOF)technique.The electron mobility of Cs_(3)Bi_(2)I_(9) crystal is obtained approximately of 4.33 cm^(2)·V^(-1)·s^(-1).The carrier mobility life product(μτ)of Cs_(3)Bi_(2)I_(9) crystal is obtained~8.21×10^(-5)cm^(2)·V^(-1) by the Hecht equation,with the energy resolution of 39%at 500 V.