First-principles study of electronic properties of F-terminated silicon nanoribbons

Using first-principles calculations based on density-functional theory, we systematically investigated the electronic properties of F-terminated silicon nanoribbons with both zigzag shaped edges (ZSiNRs) and armchair edges (ASiNRs). The results show that all the F-terminated ASiNRs are nonmagnetic semiconductors regardless of their widths. For the F-terminated ZSiNRs, the antiferromagnetic semiconductors state is the most stable one. Although the variations trend of band gaps of F-terminated SiNRs with the increase of the ribbon width is the same as that of H-terminated SiNRs, F-terminated SiNRs have lower band gaps than those of H-terminated SiNRs because of the σ–π mixing effect. These results show that F-terminated SiNRs have rich electric properties with potential applications in silicon-based electronic and spintronic nanodevices.