Thermoelectric Parameter Modeling of Single-Layer Graphene Considering Carrier Concentration and Mobility with Temperature and Gate Voltage

Abstract

Single-layer graphene (SLG) sheets can exhibit thermoelectric properties under the control of gate voltage. The controlled factors and regulation mechanism of SLG thermoelectric properties have become research hotspots. In this paper, a SLG thermoelectric parameter model considering carrier concentration and mobility with temperature and gate voltage is proposed. Based on the proposed model, the square resistance ( $R_{\mathrm {s}}$ ) and Seebeck coefficient ( $S$ ) of the SLG are calculated. The results show that the maximum value of $R_{\mathrm {s}}$ decreases from 5.8 $\text{K}\Omega $ to 3.2 $\text{K}\Omega $ at the Dirac voltage when the temperature increases from 100 K to 500 K. A large and stable $S$ can be obtained at high voltages and temperatures. The maximum value of $S$ can reach $161.3~\mu \text{V}$ /K at $T = 500$ K, exhibiting a more obvious thermoelectric characteristic. Simultaneously, the saturation law of the power factor ( $Q$ ) with the change of gate voltage and the amplitude regulation of $Q$ by temperature are obtained. This work can provide a theoretical basis for analyzing the thermoelectric characteristics of SLG.