Theoretical investigation of the electronic structure and anisotropic optical properties of quasi-1D Sb_2Se_3 photovoltaic absorber materials

摘要

Sb(2)Se(3)is a nontoxic, environmentally friendly photovoltaic absorber material with both a narrow bandgap and high absorption coefficient. The optical properties of Sb(2)Se(3)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 Sb(2)Se(3)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 5pand Se 4phybridized 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 10(5) cm(-1).