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

Highlights: • Zr₂CO₂ and MoSe₂ monolayers can form type II heterostructure. • Zr₂CO₂/MoSe₂ heterostructure undergoes the transition from semiconductor to metal under −4% strain. • The photocatalytic efficiency of Zr₂CO₂/MoSe₂ heterostructure is generally enhanced under strain. • The CBM and VBM under 0% strain are mainly from the Zr₂CO₂ and MoSe₂ layers, respectively. 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.