Enhancement of thermoelectric properties in graphene nanoribbons modulated with stub structures

The thermoelectric properties in graphene nanoribbons modulated with stub structures are studied using atomistic simulation of electron and phonon transport. The results show that the phonon transport is dramatically suppressed by the elastic scattering of the stub structure; while the thermopower S can be enhanced by a few times of magnitude. This leads to a strong enhancement of the figure of merit (ZT). Moreover, it is found that the enhancement of ZT can be effectively tuned by modulating geometric parameters of the stub and edge shapes, which offers an effective way to improve the thermoelectric performance of graphene nanoribbons.