基于多体摄动理论的CaO电子能带结构及光吸收谱的研究

Electronic band structure and optical absorption spectrum of CaO from many-body perturbation theory

使用多体摄动理论研究了碱土金属氧化物CaO的电子激发态和光吸收谱.运用GW近似方法来改进DFT对电子交换关联的处理,并计算了CaO电子能带结构.考虑到电子与空穴的相互作用,运用二粒子格林函数理论来求解Bethe-Salpeter方程,计算电子-空穴激发态,并在此基础上计算光吸收谱.计算结果 CaO能隙为7.0 e V,与实验结果 7.1 e V符合很好;并且CaO光吸收谱的理论结果与实验数据也相符合.

This paper reports the electronic band structure and the optical absorption spectrum of alkaline-earth metal oxide CaO, using many-body perturbation theory. The quasiparticle band structure is calculated within the GW approximation. By taking the electron-hole interaction into consideration, electron-hole pair states and optical excitations are obtained by solving the Bethe-Salpeter equation for the electron-hole two-particle Green function. The calculated band gap for CaO is 7.0 eV, which is in good agreement with the experimental result of 7.1 eV. The theoretical results of optical absorption spectrum for CaO are also in agreement with the experimental data.