Intervalley scattering in GaAs(111)-supported silicene.

In this paper, we investigated the valley transport properties of silicene on a GaAs(111) substrate. Hydrogen atoms as intercalation substantially weaken the interaction between silicene and GaAs(111) substrate. Thus, the equivalent intervalley scattering between K valleys and the non-equivalent intervalley scattering between Γ and K valleys were studied. The effects of external temperature, the distance Lz between silicene and the substrate, and the buckling height d of silicene on intervalley scattering were also considered. Our results showed that the intervalley scattering rates of silicene on GaAs(111) were about 1011-1012 s-1, which indicate that the weakened interaction between silicene and the substrate can effectively reduce intervalley scattering rates. The equivalent intervalley scattering of silicene was insensitive to changes of the distance Lz between silicene and the substrate and the buckling height d of silicene, but the non-equivalent intervalley scattering was greatly affected by these changes. The research results have laid a theoretical foundation for the study of the transport properties and application of silicene on semiconductor substrates.