Remarkable thermopower property enhancement in two-dimensional SiC via B and N doping and magnetic field

Abstract

DFT-based tight binding theory calculations and the Kubo conductivity formula were used to investigate the thermopower properties of 2D SiC with different impurity concentrations and magnetic field. The electronic and thermal properties were studied for cases that a carbon replaced with B (BC) and N (NC) atoms. The impurity concentration has been controlled by varying the number of cells from n2 [two unit cells] to n5 [five unit cells]. The electronic structure of the doped SiC has been strongly modified with the impurity type and the created band gap is sensitive to impurity concentration and field strength. In all selected structures, regardless of the impurity type, the subband splitting and the band gap reduction are caused by the magnetic field. Selective doped structures have thermal properties that are dependent on the type and concentration of impurity and the strength of the magnetic field. As a result of the investigations, we are able to conclude (i) structures that contain lower impurity concentrations have larger thermal properties, (ii) doped structures containing BC impurities exhibit higher thermal properties than doped structures containing NC impurities and (iii) magnetic fields have a stronger influence on structures with lower impurity concentrations.