TY - JOUR

T1 - Thermoelectric properties of finite graphene antidot lattices

AU - Gunst, Tue

AU - Markussen, Troels

AU - Jauho, Antti-Pekka

AU - Brandbyge, Mads

N1 - ©2011 American Physical Society

PY - 2011

Y1 - 2011

N2 - We present calculations of the electronic and thermal transport properties of graphene antidot lattices with a finite length along the transport direction. The calculations are based on the π-tight-binding model and the Brenner potential. We show that both electronic and thermal transport properties converge fast toward the bulk limit with increasing length of the lattice: only a few repetitions (≃6) of the fundamental unit cell are required to recover the electronic band gap of the infinite lattice as a transport gap for the finite lattice. We investigate how different antidot shapes and sizes affect the thermoelectric properties. The resulting thermoelectric figure of merit, ZT, can exceed 0.25, and it is highly sensitive to the atomic arrangement of the antidot edges. Specifically, hexagonal holes with pure armchair edges lead to an order-of-magnitude larger ZT as compared to pure zigzag edges. We explain this behavior as a consequence of the localization of states, which predominantly occurs for zigzag edges, and of an increased splitting of the electronic minibands, which reduces the power factor S2Ge (S is the Seebeck coefficient and Ge is the electric conductance).

AB - We present calculations of the electronic and thermal transport properties of graphene antidot lattices with a finite length along the transport direction. The calculations are based on the π-tight-binding model and the Brenner potential. We show that both electronic and thermal transport properties converge fast toward the bulk limit with increasing length of the lattice: only a few repetitions (≃6) of the fundamental unit cell are required to recover the electronic band gap of the infinite lattice as a transport gap for the finite lattice. We investigate how different antidot shapes and sizes affect the thermoelectric properties. The resulting thermoelectric figure of merit, ZT, can exceed 0.25, and it is highly sensitive to the atomic arrangement of the antidot edges. Specifically, hexagonal holes with pure armchair edges lead to an order-of-magnitude larger ZT as compared to pure zigzag edges. We explain this behavior as a consequence of the localization of states, which predominantly occurs for zigzag edges, and of an increased splitting of the electronic minibands, which reduces the power factor S2Ge (S is the Seebeck coefficient and Ge is the electric conductance).

U2 - 10.1103/PhysRevB.84.155449

DO - 10.1103/PhysRevB.84.155449

M3 - Journal article

SN - 0163-1829

VL - 84

SP - 155449

JO - Physical Review B Condensed Matter

JF - Physical Review B Condensed Matter

IS - 15

ER -