Enhanced Seebeck effect in graphene devices by strain and doping engineering

TL;DR

This paper demonstrates that combining strain and doping engineering in graphene devices significantly enhances the Seebeck coefficient, reaching over 1.4 mV/K, which could improve applications in sensors.

Contribution

The study introduces a method to enhance graphene's thermoelectric properties by simultaneously applying strain and doping, achieving larger conduction gaps and Seebeck coefficients.

Findings

Seebeck coefficient exceeds 1.4 mV/K in engineered graphene heterojunctions

Local strain causes Dirac cone misalignment, doping shifts energy levels

Enhanced thermoelectric performance suggests improved sensor applications

Abstract

In this work, we investigate the possibility of enhancing the thermoelectric power (Seebeck coefficient) in graphene devices by strain and doping engineering. While a local strain can result in the misalignment of Dirac cones of different graphene sections in the k-space, doping engineering leads to their displacement in energy. By combining these two effects, we demonstrate that a conduction gap as large as a few hundreds meV can be achieved and hence the enhanced Seebeck coefficient can reach a value higher than 1.4 mV/K in graphene doped heterojunctions with a locally strained area. Such hetero-channels appear to be very promising for enlarging the applications of graphene devices as in strain and thermal sensors.