静水压对立方钙钛矿CsSnX_(3)(X=I,Br,Cl)光电性质的第一性原理探究  

First-principles study of photoelectric properties of cubic perovskites CsSnX_(3)(X=I,Br,Cl)under hydrostatic pressure

作　　者：褚慧琪 赵省贵[1] 李爽 陈立勇[1] 张涛[1] CHU Hui-Qi;ZHAO Sheng-Gui;LI Shuang;CHEN Li-Yong;ZHANG Tao(School of Science,Xi’an University of Science and Technology,Xi’an 710600,China)

机构地区：[1]西安科技大学理学院,西安710600

出　　处：《原子与分子物理学报》2023年第4期115-123,共9页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11804272,11974275);陕西省重点科技创新团队项目(2019TD-026)。

摘　　要：全无机无铅卤化物钙钛矿已经成为重要的新一代太阳能电池材料.采用密度泛函理论的第一性原理研究了不同静水压下CsSnX_(3)(X=I,Br,Cl)材料的晶体结构,电子结构和光学性能,并分析了其内在联系.结果表明施加静水压可使材料中Sn-X键长减小,使原子之间的耦合增强,带隙值减小,且随着卤族元素半径的增大,压力效应越明显;随着压力的增加,材料的吸收系数和复折射率增大,吸收光谱出现红移现象,在可见光区和近红外光区吸收增强.相比CsSnBr_(3)和CsSnCl_(3),CsSnI_(3)在可见光区吸收最佳且受压力作用影响最小,更适用于钙钛矿太阳能电池材料.All-inorganic and Pb-free halide perovskites have become an important new generation of solar cell materials.In this work,we investigated the crystal structures,electronic structures and optical properties of CsSnX_(3)(X=I,Br,Cl)materials under different hydrostatic pressures and analyzed their intrinsic relations by using the first principles method based on the density functional theory.The results show that the applied hydrostatic pressure reduces the length of Sn-X bond,resulting in the enhancement of interatomic coupling and then a decrease in the band gap value.Further,the pressure effect becomes more obvious as the radius of halogen atoms increases.With increasing the pressure,the values of absorption coefficient and complex refractive index are increased.Moreover,the absorption spectrum is red-shifted and the absorption in the visible and near infrared regions is enhanced.Compared with CsSnBr_(3)and CsSnCl_(3),the CsSnI_(3)has the best absorption in the visible region and is least affected by pressure.Therefore it is more suitable for perovskites solar cell materials.

关 键 词：光学性质 电子结构 第一性原理 卤化物钙钛矿 静水压力 

分 类 号：O482[理学—固体物理]