Tunable electronic structure, interfacial and optical properties of the tellurene/ZnSe van der Waals heterostructures

Based on the first-principles calculations, we theoretically investigate the electronic structure, interfacial and optical properties of the tellurene/ZnSe (namely α- and γ-Te/ZnSe) van der Waals heterostructures (vdWHs). In the most stable stacking pattern, the α-Te/ZnSe vdWH exhibits an indirect band gap of 0.41 eV and forms a type-I band alignment, while the γ-Te/ZnSe vdWH possesses a p-type Schottky contact with a favorable Schottky barrier height of 0.29 eV at the interface of the γ-Te and ZnSe monolayer. Interestingly, the transition from type-I band alignment to type-II and type-III one can be achieved in the α-Te/ZnSe vdWH by applying 3.0% and 6.7% biaxial compressive strain, respectively, while the transition from p-type Schottky contact to Ohmic contact may be obtained in the γ-Te/ZnSe vdWH under 3.5% biaxial compressive strain. In final, the observed maximum optical absorption coefficients of the α- and γ-Te/ZnSe vdWHs is 23% and 20%, respectively, and the redshifted and/or blueshifted optical absorption peaks can be effectively modulated by the biaxial strain. The obtained results may provide a robust theoretical basis for designing of the tunable Schottky barrier and/or optoelectronic devices based on the tellurene/ZnSe vdWHs.