Improved thermoelectric properties of AB stacking bilayer graphene by Sr-intercalation according to chemical potential

Abstract

This study investigated the use of graphene intercalation compounds as thermoelectric (TE) materials. The electronic and TE properties of AB stacking bilayer graphene (BG) with Sr-intercalation were investigated using Density Functional Theory (DFT) ab initio calculations and the self-consistent full potential linearized augmented plane wave (FP-LAPW) approach. The theoretical TE properties were calculated using the Boltztrap2 package’s semi-classical Boltzmann transport equations (BTE) approximation asset. By breaking the BG’s symmetry, The findings demonstrated that atom intercalation could impact electronic and TE properties and contribute to the lifting degeneracy between the charge neutrality point and the Fermi level. Moreover, the calculated TE properties show that the intercalation of Sr in AB stacking BG proved the high values of the Seebeck coefficient for the n-type and p-type behavior and lower values of thermal conductivity leading to an increase of figure of merit values reaching 3.3 at room temperature. These findings imply that Sr-intercalated material in BG has TE device-relevant properties. Furthermore, at very low temperatures (100 K), the Sr-intercalated material exhibits outstanding thermoelectric characteristics, making it perfect for generating electricity from waste heat or cooling microelectronics.