Realizing n-type doping and high carrier mobility of silicene by decamethylcobaltocene molecular adsorption

Abstract

In this work, the structural and electronic properties of silicene with decamethylcobaltocene (DMC) molecular doping are investigated by density functional theory to improve its semiconductor properties. DMC molecule with strong electron-donating ability is physisorbed on silicene. An interfacial charge transfer between silicene and DMC molecule occurs, then the location of Fermi energy is modulated lower than the Dirac point of silicene with 0.273 eV ‒ 0.282 eV. Consequently, n-type doped silicene is realized. Meanwhile, a band gap of 0.024 eV ‒ 0.032 eV opens in silicene. Moreover, silicene maintains a high carrier concentration (3.426 × 1013 ‒ 3.518 × 1013 cm−2) and carrier mobility (13.839 × 104 cm2 V−1 s−1 for electrons and 5.428 × 104 cm2 V−1 s−1 for holes) with anisotropy. This work opens possible applications of silicene in photonic and electronic devices.