Edge-disorder-induced optimization of thermoelectric performance of finite-length graphene nanoribbons

摘要

Effects of edge disorder on thermoelectric performance of graphene nanoribbons (GNRs) were investigated through computational simulations based on the non-equilibrium Green's function method combined with the tight-binding method. We found that the thermoelectric power factor PF can be optimized by adjusting the length, L-g, of GNRs with edge disorder concentration C-d. For example, PF of zigzag-edged GNRs with a C-d of 10 % at room temperature and at the Fermi energy shows a maximum value of 33mW/(m K-2) at L-g=210nm. Both the maximum PF and optimum L-g decrease with increasing C-d. The maximum PF is theoretically explained in terms of the crossover from the ballistic transport regime to the Anderson's localization regime. Copyright (c) 2016 John Wiley & Sons, Ltd.