Advanced energy materials and devices: a computational DFT perspective

The pursuit of high-efficiency heat-to-electricity conversion is one of the indispensable driving forces toward future renewable energy production. The two-dimensional (2D) transition metal dichalcogenide, such as molybdenum disulfide (MoS₂), is at the forefront of research due to its outstanding heat propagation features and potential applications as a thermoelectric material. Using the first-principles density functional theory coupled with the semi-classical Boltzmann transport equation within the constant relaxation time approximation, we present the thermoelectric and energy transport in the bulk 2H and monolayer MoS₂ material system. In order to advance the underlying physics, we calculate several crucial transport parameters such as electrical conductivity, electronic thermal conductivity, Seebeck coefficient, and power factor as a function of the reduced chemical potential for different doping types and temperatures, in addition to the electron energy dispersion relation of the material system. Our comprehensive study employs the Shankland interpolation algorithm and the rigid band approximation to attain a high degree of accuracy. This thorough investigation reveals the high Seebeck coefficient of 1534 and 1550 μV/K at 500 K for the bulk 2H and monolayer MoS₂, respectively. Furthermore, the ultrahigh power factor values of 9.21 × 10¹¹ and 3.69 × 10¹¹Wm⁻¹K⁻²s⁻¹ are shown at 800 K in the bulk 2H and monolayer MoS₂, respectively. Based on the power factor results, our in-depth analysis demonstrates that the bulk 2H MoS₂, when compared to monolayer MoS₂, exhibits great potential as a promising semiconducting thermoelectric material for advanced high-performance energy device applications.