Electronic and thermoelectric properties of atomically thin C3Si3/C and C3Ge3/C superlattices

Abstract

The nanostructuring of graphene into superlattices offers the possibility of tuning both the electronic and thermal properties of graphene. Using classical and quantum mechanical calculations, we have investigated the electronic and thermoelectric properties of the atomically thin superlattice of C3Si3/C (C3Ge3/C) formed by the incorporation of Si (Ge) atoms into graphene. The bandgap and phonon thermal conductivity of C3Si3/C (C3Ge3/C) are 0.54 (0.51) eV and 15.48 (12.64) W m−1 K−1, respectively, while the carrier mobility of C3Si3/C (C3Ge3/C) is 1.285 × 105 (1.311 × 105) cm2 V−1 s−1 at 300 K. The thermoelectric figure of merit for C3Si3/C (C3Ge3/C) can be optimized via the tuning of carrier concentration to obtain the prominent ZT value of 1.95 (2.72).