Structural and electromagnetic properties of double C chains decorated zigzag silicene nanoribbon

•Nearly straight C chains lead to a transverse contraction of the ribbon width.•Double C chains decorated ZSiNRs are always metallic.•Defect states contributed from double C chains across the Fermi level.•Perfect and double C chains decorated ZSiNRs have FM and AFM ground states respectively.

Using the first-principles calculation, we investigate the structural and electromagnetic properties of the zigzag edge Si nanoribbons (ZSiNRs) decorated with double C chains. The results show that double C chains decorated ZSiNRs are always metallic independent of the ribbon width. The defect states contributed from double C chains are composed of two degenerated bands across the Fermi level. The perfect ZSiNR has a FM ground state, while double C chains decorated one have an AFM ground state. The C chains are always close to straight ones thereby resulting in a transverse contraction near the C chains and thus the ribbon width. The C–Si bond displays an ionic binding feature and the C–H bond is a typical covalent one because of the electronegativity and the bound force difference between H, C and Si atoms.

Graphical abstractStructure and charge density distribution for (a) 6-ZSiNR-2C(1, 6), (b) 10-ZSiNR-2C(1, 10). Blue and red colors represent the lowest and the highest magnitude of charge density.Figure optionsDownload full-size imageDownload as PowerPoint slide