First-principles study on band gaps and transport properties of van der Waals WSe2/WTe2 heterostructure

Abstract

Abstract Transition metal disulfides (TMDCs) have attracted extensive attention in recent years for their novel physical and chemical properties. Based on the first-principles calculations together with semi-classical Boltzmann transport theory, we explored the electronic structures and transport properties of van der Waals WSe2/WTe2 heterostructure. WSe2/WTe2 heterostructure has distinctive hexagon structure and isotropic thermal transport properties. To prove the accuracy of band structure, both Perdew–Burke–Eruzerhof (PBE) and Heyd–Scuseria–Ernzerhof (HSE06) have been used to calculate the band structures. We simulated the band structures under uniaxial and biaxial strains from −8% to +8% and found that all band gaps calculated by HSE06 are larger than results calculated by PBE. More importantly, it was found that when the biaxial strain reaches ±8%, it undergone semiconductor to metal and the dynamic stabilities of WSe2/WTe2 heterostructure have been predicted at the same time. We calculated the mobilities of electrons and holes and found that the mobility of holes is larger than that of electrons. The obtained lattice thermal conductivity (LTC) of WSe2/WTe2 heterostructure at room temperature (70.694 W/mK) is significantly higher than other transition metal tellurium and transition metal selenium, such as PdSe2 (2.91 W/mK) and PdTe2 (1.42 W/mK) monolayers. Our works further enrich studies on the strain dependence of electronic structures and predicted high LTC of WSe2/WTe2 heterostructure, which provide the theoretical basis for experiments in the future.