Silicane as an inert substrate of silicene: A promising candidate for FET

Opening up a band gap without lowering high carrier mobility and finding a suitable substrate material are a challenge for designing silicon-based nanodevices. Using density functional theory calculations incorporating vdW corrections, we find that the semiconducting silicane monolayer is free of dangling bonds, providing an ideal substrate for silicene to sit on. The nearly linear band dispersion character of silicene with a sizable band gap (44-61 meV) opening is obtained in all heterobilayers (HBLs). We also find that the effective masses of electrons and holes near the Dirac point (ranging from 0.033 to 0.045m₀) are very small in HBLs, and thus high carrier mobility (10⁵cm² V^-1 s^-1) of silicene is expected. These characteristics of HBLs can be flexibly modulated by applying bias voltage or strain, suitable for the high-performance FET channel operating at room temperature.