Comparative study on transport and optical properties of silicon carbide nanoribbons with different terminations

Silicon carbide nanoribbons (SiCNRs) are a novel layered material with potential value in the field of nanodevices. Based on the first-principles calculation, we investigated the effects of different terminations on the bandgap, transport, and optical properties of SiCNRs. The results show that for infinite width nanoribbons, the bandgap of SiCNSs with translational periodicity is increased and the optical anisotropy is more pronounced compared with that of SiCNTs with circular periodicity. For finite-width SiCNRs, impurity-like levels appear in the bandgap, which originate from the dispersion of the energy bands due to dangling bonds at the edges and nano-size effects, respectively. The dangling bonds are saturated with hydrogen atoms for hydrogen-passivated SiCNRs (H–SiCNRs), the energy levels are more discretized and the bandgap is reduced. Simulation of transport properties of different terminations shows that the variation range hopping mechanism caused by finite width is the dominant mechanism below room temperature, and the optical phonon scattering is the dominant mechanism above room temperature. In addition, the dielectric response of H–SiCNRs appeared in the deep-UV region. These findings are favorable for the application of SiC nanomaterials in optoelectronic devices. Graphical abstract