The effect of biaxial strain on the thermoelectric properties of two-dimensional layered MoSe2

Two-dimensional layered MoSe2 demonstrates exceptional potential for thermoelectric conversion and waste heat recovery applications, owing to its superior electrical transport properties derived from structural plasticity and the high electronegativity of Se atoms. This study systematically examines the effects of biaxial strain on the thermal transport and thermoelectric properties of MoSe2 through first-principles calculations. The results reveal that tensile strain induces a monotonic reduction in lattice thermal conductivity through significant decreases in both phonon lifetime and group velocity. Regarding thermoelectric performance, while tensile strain enhances both p-type and n-type MoSe2, the n-type variant shows more pronounced improvement. The thermoelectric figure of merit increases from 0.066 to 0.191 under 2% tensile strain at 300 K, reaching 1.061 under 4% strain at 800 K. These findings not only confirm the excellent thermoelectric properties of n-type MoSe2 but also reveal the important role of strain engineering in modulating the thermoelectric properties, suggesting that n-type MoSe2 has great potential as a thermoelectric material.