AZrX_(3)(A=Ba,Ca;X=S,Se,Te)钙钛矿结构及光电特性的第一性原理研究

First-principles Investigation on the Structure and Photoelectric Properties of AZrX_(3)(A=Ba,Ca;X=S,Se,Te)Perovskites

基于密度泛函理论的第一性原理计算方法,考虑自旋轨道耦合(SOC)效应,采用Heyd-Scuseria-Ernzerhof(HSE06)杂化泛函对带隙进行修正,系统研究了AZrX_(3)(A=Ba,Ca;X=S,Se,Te)无铅钙钛矿的晶体结构、电子结构和光学性质。结果表明,AZrX_(3)钙钛矿为直接带隙半导体材料,且材料的容忍因子介于0.85~0.95之间、形成能位于-1.09~-1.83 eV/atom之间、分解能介于-0.09~0.06 eV/atom之间,表明AZrX_(3)钙钛矿具有稳定的结构。其中,BaZrS_(3)具有空穴有效质量小(0.21 m0)、载流子迁移率高、可见光吸收范围宽、光吸收系数高(~4×10^(5)cm^(-1))等特点,且光谱极限最大效率(SLME)可达32.36%,高于CH_(3)NH_(3)PbI_(3)(~30%),是很有前途的太阳电池材料。AZrSe_(3)和AZrTe_(3)的光电性质计算显示它们也是潜在的光电材料。AZrX_(3)钙钛矿的研究可为寻找高效无铅的光电材料提供一个新的途径。

Considering spin-orbit coupling(SOC)effect,using Heyd-Scuseria-Ernzerhof(HSE06)hybrid functional to correct the band gap,the structure,electronic and optical properties of AZrX_(3)(A=Ba,Ca;X=S,Se,Te)lead-free perovskites were systematically studied by the first-principles calculation method of density functional theory.The results show that AZrX_(3) perovskites are direct bandgap semiconductor materials.The tolerance factors of AZrX_(3) are between 0.85 and 0.95,the formation energies are between-1.09 eV/atom to-1.83 eV/atom,and the decomposition energies are between-0.09 eV and 0.06 eV,which indicates that AZrX_(3) have stable structures.Among them,BaZrS_(3) is a promi-sing solar cell material,because of its small hole effective mass(0.21 m0),high carrier mobility,wide visible light absorption range,and high light absorption coefficient(~4×10^(5)cm^(-1)),as well as the spectroscopic limited maximum efficiency(SLME)32.36%,which is higher than that of CH_(3)NH_(3)PbI_(3)(~30%).The calculation of photoelectric properties of AZrSe_(3) and AZrTe_(3) shows that they are also potential optoelectronic materials.The study of AZrX_(3) perovskites provide a new way to search for high-efficiency lead-free optoelectronic materials.