The electronic structures and predominant thermoelectric performance of the twisted InSb/Graphene bilayer

Abstract

Due to the superior performance of graphene and the character of zero band gap, the energy band-gap engineering of graphene has always been the focus of research. We employed the first-principles calculation to study the twisted InSb/graphene bilayer, the band structures of the four InSb/graphene bilayer construction and the twisted models have been calculated. From the results we find that by the torsion between InSb and graphene layers successfully opened the Dirac point of the graphene in the Sb-down InSb/graphene model. At the torsion angle of 30°, the band gap reaches 180 meV. When applying compressive or tensile strain its band gap becomes smaller, it's just that the band gap is more sensitive to tension than compression. Focus on the Sb-down InSb/graphene model with two special torsion angles 19.11° and 30°, we also calculated the thermoelectric (TE) properties. At the temperature of 900 K, the maximum figure of merit ZT can reach 5.2 for p-type doping Sb-down InSb/graphene model with the torsion angle of 30°. • The torsion between the InSb and graphene monolayer makes the Dirac point of the graphene open in the Sb-down InSb/graphene model. • At the temperature of 900 K, the maximum figure of merit ZT can reach 5.2 for p-type doping Sb-down InSb/graphene model with the torsion angle of 30°. • At 900K, the maximum figure of merit ZT can reach 2.5 for n-type doping Sb-down InSb/graphene model with the torsion angle of 19.11.