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

Abstract

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, Lg, of GNRs with edge disorder concentration Cd. For example, PF of zigzag‐edged GNRs with a Cd of 10 % at room temperature and at the Fermi energy shows a maximum value of 33 mW/(m K2) at Lg = 210 nm. Both the maximum PF and optimum Lg decrease with increasing Cd. The maximum PF is theoretically explained in terms of the crossover from the ballistic transport regime to the Anderson's localization regime. Copyright © 2016 John Wiley & Sons, Ltd.