Enhanced Seebeck effect in gated O-shaped Kekulé graphene junctions.

The Seebeck effect in graphene with uniform Kekulé lattice distortion has been studied using the tight-binding model combined with the nonequilibrium Green's function method. The numerical results of this work show that the Seebeck coefficient of the O-shaped Kekulé graphene can be enhanced by modulating the gate voltage. At room temperature (T ≈ 300 K), the Seebeck coefficient for the armchair nanoribbon is S c ≈ 1370 μV/K and for the zigzag nanoribbon is S c ≈ 1260 μV/K. At low temperature (T ≈ 128 K), the Seebeck coefficient for the armchair nanoribbon is S c ≈ 2500 μV/K. In addition, the nano-structuration of the O-shaped Kekulé graphene layer induces an anisotropic behavior in the Seebeck effect. Our work provides an idea for the fabrication of efficient and controllable thermoelectric effect devices. [ABSTRACT FROM AUTHOR]