Atomic‐Layered MoS₂ as a Tunable Optical Platform

Monolayer molybdenum disulfide (MoS₂), a direct bandgap semiconductor with atomic thickness, provides significant advantages in many applications including high‐performance electronics, light emitters, and photodetectors/sensors. Controlling the electronic and optical properties of atomic‐layered MoS₂ is extremely important for its practical applications. Interestingly, modulating the optical properties by physical routes, such as layer thickness, twist angle, tensile strain, temperature, gas physisorption and electrical doping, is more attractive, as these methods can control optical properties in real‐time, reversible, and in situ. The physical routes would be beneficial for understanding the fundamentals of electronic and optical properties of atomic‐layered MoS₂, and also for its promising application in advanced optical materials and next‐generation electronic devices. This review highlights recent, state‐of‐the‐art research on tuning the optical properties of atomic‐layered MoS₂ (including monolayer and few‐layer MoS₂). Physical routes and proposed mechanisms of these modulations are discussed. Crystal structures and electronic band properties of atomic‐layered MoS₂ are also reviewed, as they play important roles in understanding the modulation mechanisms. Finally, potential optical applications in electronic and optoelectronic devices based on tunable optical features are described, and a future prospective in this exciting field is presented.