Tunable electronic properties of CdS nanoribbons by edge effects

Based on first-principles calculations, the electronic properties of Cadmium Sulfide nanoribbons (CdSNRs) have been studied with both zigzag (Z-CdSNRs) and armchair shaped edges (A-CdSNRs). For Z-CdSNRs, the structures with both edges decorated by H or F atoms show half-metallic or semiconducting properties, respectively. Only S-dominated edge decorated by H/F atoms, Z-CdSNRs show metallic properties. Only Cd-dominated edge is hydrogenated, Z-CdSNRs can be observed from a metallic to half metallic transition. But instead of fluorinated, the structures show the metallic properties. However, either edge or both edges are hydrogenated or fluorinated, A-CdSNRs exhibit semiconducting properties, and their band gap decreases monotonically with increasing ribbons width (n). When a stress is applied on the half-hydrogenated A-CdSNRs, their band gap displays a steady decrease trend. Moreover, A-CdSNRs are more stable than Z-CdSNRs, while the hydrogenated systems are more stable than fluorinated systems. The results show that different structures of CdSNRs decorated with the different edges can play different nature as semiconducting - half-metallic - metallic properties. The research has important theoretical significance for the electronic design and assembly of CdSNRs structures, and provides a new perspective for the potential application of CdSNRs in nanoelectronics.