Two-step fabrication of large-scale MoS2 hollow flakes

Recently, molybdenum disulfide (MoS2) has become a superstar material due to its outstanding optical and electronic performance, and its use as a promising candidate for optoelectronic devices. Here, we report the synthesis of large-scale two-dimensional (2D) MoS2 hollow flakes through a two-step method by utilizing thermal sulfurization-evaporation. Optical microscopy, scanning electron microscopy, AFM, Raman and PL spectroscopy analyses revealed that a solid MoSz flake has a tapered multi -layered structure with an edge region of a single layer, and the hollow flake is a monolayer. The formation process of the 2D MoS2 hollow flakes is discussed on the basis of the experimental analyses. Such 2D MoS2 hollow flakes are envisaged to be novel templates for constructing 2D lateral p-n heterojunctions and 2D-1D heterostructures.