Electrical Transport and Thermoelectric Properties of Cr-doped Monolayer MoS₂and WS₂via Density Functional Theory and Boltzmann Transport Simulation

This work computationally studies the monolayer (ML) MoS2, WS2 and the substitutional Cr-doped ones. The lattice parameters, band structure, density of state are calculated from the density functional theory (DFT). The electron mobility and Seebeck coefficient are estimated from the linearized Boltzmann transport equation (BTE). Compared with ML-MoS2 and ML-WS2, the direct band gaps of Cr-doped ML-MoS2 and ML-WS2 are reduced via DFT calculation. For the Cr-doped ML-MoS2 and ML-WS2, estimated by the linearized BTE, the values of electron mobility are about 5.7 and 11.8 times variations when the doping concentration increase from 108 to 1012 cm-2 at room temperature. The magnitudes of electron Seebeck coefficient of Cr-doped ML-MoS2 and ML-WS2 are about 1220 and 1210 μV/K at the doping concentration of 108 cm-2.