Study on the PhotoThermoelectric Characteristic of Graphene with Double-Gate

When light passes through the interface of two materials with different Seebeck coefficients (S), a temperature gradient will be occurred at the interface, causing photo-thermoelectric effect, which in turn produces photocurrent. Since photocurrent is positively correlated with the difference of Seebeck coefficient of the material and negatively correlated with the resistance of the material, a method for calculating the thermoelectric parameters of graphene with double-gate structure is proposed in this paper. Taking the back gate voltage as a global variable and the top gate voltage as a local variable, the resistance of graphene sheets in different regions is regulated. By solving the resistance of graphene sheets in two regions with top gate and without top gate, their Seebeck coefficients can be obtained. The results show that under the control of the global back gate voltage, a small range of fine adjustment of the top gate voltage can accurately achieve precise control of the resistance and Seebeck coefficient of different regions of the graphene sheet. This paper provides a theoretical basis for the subsequent study on the photoelectric characteristics of graphene.