Heterostructures of two-dimensional layered materials: intriguing photo-physics and emerging applications

Heterostructures of two-dimensional (2D) layered semiconducting materials with conventional semiconductors and metal nanostructures are gaining a lot of attention due to their superior properties as compared to their individual counterparts. 2D layered interfaces are often created by post growth wet transfer method, which may alter its properties and eventually lead to poor device performance. In-situ growth of heterostructures with seamless interface is highly desirable for high performance device applications. In this talk, I will give an overview of our ongoing research on large area CVD/chemical growth of monolayer graphene, monolayer MoS₂, WS₂, PdSe₂, Bi₂Se₃, Bi₂O₂Se, MXene, graphene/ZnO, and MoS₂/TiO₂, MoS₂/WS₂, Bi₂O₂Se/Perovskite heterostructures, ZnO/WS₂/ZnO quantum well etc. and their applications in optoelectronics, energy, environment, biosensing. As a case study, I shall elaborate on the physics of coupled charge transfer dynamics and doping in MoS₂/WS₂ heterojunction, and next, on the control and manipulation of many-body quasiparticles (trions and biexcitons) in ZnO/WS₂/ZnO 2D quantum wells. The importance of a rational design of 2D heterostructures for various emerging applications will be highlighted in this talk. (author)