Impact of Lattice Volume on the Band Gap Broadening of Isovalent S-Doped CuInSe2
S掺杂CuInSe2导致的体积变化对其禁带宽度的影响

The electronic structure of pure and S-doped chalcopyrite CuInSe2 is investigated using a first-principles pseudopotential method in the generalized gradient approximation.The calculation indicates that the band gap of CuInSe2 broadens as S-doping concentration increases.We find that the decreased lattice volume due to isovalent S-doping in CuInSe2 has a significant impact on the band gap broadening phenomena.This physical insight is further discussed with the study of the electronic structure and bond length changes.