不同压力下CoSb_(3)电子结构和光学性质的第一性原理研究

Electronic Structure and Optical Properties of CoSb_(3) Under Different Pressures:A First Principles Study

基于密度泛函理论(DFT)的第一性原理,采用广义梯度近似(GGA)研究了不同压力下CoSb_(3)的能带结构、态密度、声子色散曲线、拉曼光谱和红外光谱的变化规律。在0~20 GPa范围内,随着施加压力强度的增加,能带带隙增加,但仍为间接带隙半导体;对CoSb_(3)的声子色散曲线分析发现,在施加0~20 GPa压力时声子色散曲线仍然没有虚频出现,这表明在此压力范围内CoSb_(3)结构稳定;在施加压力过程中拉曼光谱和红外光谱都发生了移动,拉曼光谱发生蓝移。

Based on the first principles of density functional theory(DFT),energy band structure,state density,phonon dispersion curves,Raman spectrum and infrared spectrum of CoSb_(3) under different pressures are studied.In the range of 0~20 GPa,the energy band gap increases with the increase of applied pressure,while it is still an indirect band gap semiconductor.There is still no virtual frequency in the phonon dispersion curves and the stability of the structure does not change when the pressure of 0~20 GPa is applied.In the process of applying pressure,the Raman spectrum and infrared spectrum have obvious changes,and the Raman frequency has blue shift phenomenon.