Intervalley scattering in GaAs(111)-supported silicene

Abstract

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 L_z 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 L_z 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.