Enhancement of thermoelectric properties of gamma-graphyne nanoribbons with edge modulation
Hunan Key Laboratory for Micro-Nano Energy Materials and Device and Department of Physics, Xiangtan University, Xiangtan 411105, P.R. China
Received: 26 February 2015
Received in final form: 11 April 2015
Published online: 25 May 2015
Graphyne, a sister material of graphene, is a new hot topic in present carbon-based nanomaterials research community. Taking gamma-graphyne nanoribbon as an example, we investigate the effect of edge modulation on the thermoelectric properties by means of nonequilibrium Green’s function (NEGF) in the ballistic transport region. Our simulations show that the thermoelectric performance of gamma-graphyne nanoribbons can be enhanced observably through the edge modulation (the figure of merit could exceed 1.2 at room temperature), and such enhancement strongly depends on the geometric characters of edge modulation. This evident improvement of thermoelectric efficiency mainly originates from the fact that the degraded phononic thermal conductance owning to edge phonon scattering outweighs the suppression of thermal power. Our findings further qualify gamma-graphyne as a promising candidate for thermoelectric applications and could offer useful guidance for the future thermoelectric devices design and fabrication.
Key words: Mesoscopic and Nanoscale Systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2015