First-principles study of the thermoelectric properties of strained graphenenanoribbons

Abstract

We study the transport properties, in particular the thermoelectric figure of merit (ZT), of armchair graphene nanoribbons, AGNR-N (for N = 4–12, with widths ranging from 3.7 to 13.6 Å), through strain engineering, where N is the number of carbon dimer lines across the AGNR width. We find that the tensile strain applied to AGNR-N changes the transport properties by modifying the electronic structures and phonon dispersion relationships. The tensile strain increases the ZT value of the AGNR-N families with N = 3p and N = 3p + 2, where p is an integer. Our analysis based on accurate density-functional theory calculations suggests a possible route to increase the ZT values of AGNR-N for potential thermoelectric applications.