Strain-tunable electronic and optical properties of Zr2CO2 MXene and MoSe2 van der Waals heterojunction: A first principles calculation

Zr2CO2/MoS2 heterostructure has attracted intensive attention because of its remarkable electronic and optoelectronic properties. In this paper, the van der Waals (vdW) heterostructures are constructed by stacking MoSe2 on top of Zr2CO2 MXene. The most stable stacking configuration is confirmed. Zr2CO2 and MoSe2 monolayers can form type II heterostructure, and the interfacial electronic states coupling between Zr2CO2 and MoSe2 is responsible for gap states. The effect of strain on the electronic structure and optical properties of Zr2CO2/MoS2 heterostructure is investigated theoretically. The manner in which the strain modulates the band structure of Zr2CO2/MoS2 heterostructure, including band gap, total/partial density of state, charge transfer is reported. The compressive and tensile strains can all result in the metallization of Zr2CO2/MoSe2 heterostructure. The increasing amount of charge redistribution results in the transition from semiconductor to metal with the increasing compressive and tensile strain. The photocatalytic efficiency of Zr2CO2/MoSe2 heterostructure is generally enhanced under strain. The effect of strain on optical properties is further explored.