Optical performance and growth mechanism of a 2D WS2–MoWS2 hybrid heterostructure fabricated by a one-step CVD strategy

Abstract

The construction of two-dimensional (2D) transition-metal dichalcogenide (TMDC) alloy-based vertical heterostructures can provide an alternative candidate for developing ultrathin and novel optoelectronic devices. Here, we have reported the synthesis of a 2D WS₂/Mo_1−xW_xS₂ hybrid heterostructure with a tunable x value from its inner part to peripheral region through a one-step CVD strategy. Systematic Raman and light-emission analyses have demonstrated that the as-grown hybrid heterostructure exhibits position-dependent structural and optical modulations. The growth of 2D Mo_1−xW_xS₂-based hybrid heterostructures probably originated from the variation of Mo/W concentration with time in vapor. This result provides a feasible approach to synthesize 2D alloyed TMDC-based heterostructures, which can accelerate the progress of high-performance functional optoelectronic devices.