Sb₂Se₃ is a nontoxic, environmentally friendly photovoltaic absorber material with both a narrow bandgap and high absorption coefficient. The optical properties of Sb₂Se₃ crystals are theoretically studied herein using first-principles methods. The crystal structure, electronic structure, dielectric function, and absorption coefficient are calculated. The results show that the quasi-one-dimensional structure of Sb₂Se₃ has an indirect bandgap with a value of 0.953 eV. The bottom of the conduction band and the top of the valence band are mainly formed by Sb 5p and Se 4p hybridized orbitals. For light incident along the [100], [010], and [001] directions, the real and imaginary parts of the dielectric function exhibit clearly anisotropic characteristics. The absorption coefficient is greater than 10⁵ cm⁻¹.

Sb ₂ Se ₃是一种无毒，环保的光伏吸收材料，具有窄的带隙和高吸收系数。本文中使用第一原理方法对Sb ₂ Se ₃晶体的光学性质进行了理论研究。计算晶体结构，电子结构，介电函数和吸收系数。结果表明，Sb ₂ Se ₃的准一维结构具有0.953 eV的间接带隙。导带的底部和价带的顶部主要由Sb 5 p和Se 4 p形成混合轨道。对于沿[100]，[010]和[001]方向入射的光，介电函数的实部和虚部具有明显的各向异性特征。吸收系数大于10 ⁵  cm ^-1。