We investigate thermoelectric (TE) properties of two-dimensional materials possessing two Dirac bands (a Dirac band) and a nonlinear band within the three-(two-)band model using linearized Boltzmann transport theory and relaxation time approximation. In the three-band model, we find that combinations of Dirac bands with a heavy nonlinear band, either a parabolic or a pudding-mold band, does not give much difference in their TE performance. The apparent difference only occurs in the position of the nonlinear band that leads to the maximum figure of merit (ZT). The optimum ZT of the three-band model consisting of a nonlinear band is found when the nonlinear band intersects the Dirac bands near the Fermi level. By removing the linear conduction band, or, in other words, transforming the three-band model to the two-band model, we find better TE performance (in terms of higher ZT values) in the two-band model than in the three-band model for various band gaps and effective masses of the nonlinear band.
|Original language||English (US)|
|Journal||Materials Today Communications|
|State||Published - Oct 21 2022|
Bibliographical noteKAUST Repository Item: Exported on 2022-12-20
Acknowledgements: A.D. performed first principles calculations using King Abdulaziz University (KAU)’s High Performance Computing Center (Aziz Supercomputer). He is also supported by the KAU, Saudi Arabia scholarship. E.S. and A.R.T.N acknowledge computational facilities from BRIN HPC. This work was partially supported by e-ASIA Joint Research Program.
ASJC Scopus subject areas
- Mechanics of Materials
- Materials Science(all)
- Materials Chemistry