2D WS₂: From Vapor Phase Synthesis to Device Applications

The discovery of graphene has triggered the research on 2D layer structured materials. Among many 2D materials, semiconducting transition metal dichalcogenides (TMDs) are widely considered to be the most promising ones due to their excellent electrical and optoelectronic characteristics. Tungsten disulfide (WS₂) is a kind of such TMDs with fascinating properties, such as the high carrier mobility, appropriate band gap, strong light–matter interaction with the large light absorption coefficient, very large exciton binding energy, large spin splitting, and polarized light emission. All these interesting properties can make the 2D WS₂ being highly favorable for applications in memristors, light-emitting devices, optical modulators, and many others. Here, the comprehensive review on the properties, vapor phase synthesis, electronic and optoelectronic applications of 2D WS₂ is presented. This review does not only serve as a design guideline to elevate the material quality of 2D WS₂ films via enhanced synthesis approaches, but also provides valuable insights to various strategies to improve their device performances. With the fast development of wafer-scale synthesis methods and novel device structures, 2D WS₂ can undoubtedly be a rising star for the next-generation devices in the near future.