Electrical Transport and Thermoelectric Properties of Cr-doped Monolayer MoS2 and WS2 via Density Functional Theory and Boltzmann Transport Simulation

This work computationally studies the monolayer (ML) MoS
2
, WS
2
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-MoS
2
and ML-WS
2
, the direct band gaps of Cr-doped ML-MoS
2
and ML-WS
2
are reduced via DFT calculation. For the Cr-doped ML-MoS
2
and ML-WS
2
, 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 10
⁸
to 10
¹²
cm
^-2
at room temperature. The magnitudes of electron Seebeck coefficient of Cr-doped ML-MoS
2
and ML-WS
2
are about 1220 and 1210 μV/K at the doping concentration of 10
⁸
cm
^-2
.