Effect of C-face 4H-SiC(0001) deposition on thermopower of single and multilayer graphene in AA, AB and ABC stacking

Abstract

The Seebeck coefficient in multilayer graphene is investigated within the density-functional theory, using the semiclassical Boltzmann equations and interpolating the bands in a maximally-localized Wannier functions basis set. We compare various graphene stackings (AA, AB and ABC) both freestanding and deposited on a 4H-SiC(0001) C-terminated substrate. We find that the presence of the SiC substrate can significantly affect the thermopower properties of graphene layers, depending on the stacking, providing a promising way to tailor efficient graphene-based devices.

Spin-dependent Seebeck effect and huge growth of thermoelectric parameters at band edges in H- and F-doped graphene, free-standing and deposited on 4 H -SiC(0001) C-face

“…The thermoelectric parameters at the low-energy parts of the F-impurity bands are low, since in that region, the impurity bands touch the valence band manifold. For the spindown channel of the F-doped graphene, we observe the Seebeck-coefficient and the ZT-efficiency extrema similar to these obtaned for the pure graphene close to the band crossing at the Fermi level near the K-point [37]. Less pronounced features of the same shape in the thermopower curve are visible below -1.2 eV for the spin-up…”

“…4, together with the band structures of H-and F-doped systems. In the case of hydrogen doping, the majority spin-bands close to the K-point are similar to the bands of bilayer graphene in the AB stacking or graphite [32,37] -with the difference that here the parabolic bands touch each other below the Fermi level, and the minority spin-bands open the gap close to the K-point. In the case of fluorine doping, the band gap opens at the K-point in both spin channels.…”

Photocurrent generation at ABA/ABC lateral junction in tri-layer graphene photodetector

“…The behaviors of the Seebeck coefficients are comparable to the results reported by Wierzbowska et al although the graphs look somewhat different due to different scaling of the x-axis [43]. show Raman modes that are used to identify ABA-and ABC-stacked domains in TLG [28,29,32,34].…”

Thermoelectric effect enhanced by resonant states in graphene

“…The thermopower of biased and unbiased multilayer graphene was studied in the Slonczewski-WeisMcClure model, where the effect of impurity scattering was treated in the self-consistent Born approximation 10 . The classic and spin Seebeck effects in single as well as in multilayer graphene on the SiC substrate were also investigated within ab-initio methods, 11,12 and by nonequilibrium molecular-dynamics simulations.…”