First-principles studies on the electronic structures of Cu-doped CdIn2S4 crystals

The electronic structures and densities of states of the spinel CdIn
₂
S
₄
crystals have been investigated using the first-principle density function theory and pseudopotential method in this paper. The results show that CdIn2S4 is an indirect semiconductor with the band gap of 1.44 eV. Cu doping can narrow the band gap of CdIn
₂
S
₄
to 0.88 eV. The calculated results indicate that Cu doping may be one of the most important factors influencing the photocatalytic activity of CdIn
₂
S
₄
crystals.