NaCaF3晶体的电子结构及光学性质

Study on the Electronic Structure and Optical Properties of NaCaF3

基于第一性原理超软赝势平面波方法,对钙钛矿结构NaCaF3晶体的电子结构与光学性质进行了研究.对NaCaF3晶体的结构进行了几何优化,计算了其能带结构、态密度、介电函数、能量损失函数、反射光谱和吸收光谱,获得了相关的光学性质.研究结果表明NaCaF3晶体是间接带隙化合物并具有宽带隙,而且表现出光学各向异性,其光反射峰值的位置和能量损失函数计算的结果相吻合,光学吸收边在4.989 e V处.此外,根据介电函数虚部的色散关系可推断出其在较高能量的光谱范围内具有良好的透过率.

Based on the first-principles plane wave ultrasoft pseudopotential method,the electronic structure and optical properties of perovskite structure NaCaF3 crystal were investigated.The structure of NaCaF3 crystal was optimized geometrically,and its energy band structure,density of states,dielectric function,energy loss function,reflection spectrum and absorption spectrum were calculated,and related optical properties were obtained.The result show that NaCaF3 is an indirect band gap compound with a wide band gap and exhibits optical anisotropy.The position of its light reflection peak coincides with the calculated energy loss function,and the optical absorption edge is at 4.989 eV.In addition,according to the dispersion relation of the imaginary part of the dielectric function,it can be inferred that it has a good transmittance in the higher energy spectral range.