First-principles study on optical properties of group-III doped SiCNRs

Based on first-principles calculation, the effects of replacing C or Si sites with group-III elements X (X = B, Al, Ga and In) on optical properties of SiCNRs were studied. The results have shown that, except for the intrinsic impurity like level, X Si -SiCNRs appears an acceptor level and a deep level. X C -SiCNRs appears only one deep level. In addition, SiCNRs has a significant photoelectric response in 170–180 nm, In C -ZSiCNRs also has a significant photoelectric response in visible region. SiCNRs of group-III to replace C have different dielectric responses in the near UV–visible. In C -SiCNRs presents a new dielectric response near 280 nm. • The effects of replacing C or Si sites with group-III elements on band-gap and optical properties of ZSiCNRs were studied. • Results show that the structure of doped SiCNRs is stable, and it is easier for group-III elements to replace Si than C. • A acceptor and a deep impurity level appear when Si is substituted,only a deep impurity level appears when C is substituted. • ZSiCNRs has a photoelectric response in deep ultraviolet (170–180 nm), In C -ZSiCNRs also has a one in visible region. • In the C-substitution ZSiCNRs, a new dielectric response appears near 280 nm.