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.

Fluorescence resonance energy transfer between CdSeTe/ZnS quantum dots and monolayer graphene oxide is in situ manipulated by laser irradiation.

Graphene oxide (GO) emerges as a functional material in optoelectronic devices due to its broad spectrum response and abundant optical properties. In this article, it is demonstrated that the change of optical transmittance amplitude for monolayer GO (mGO) could be up to 24.8% by an external electric field. The frequency harmonics for transmittance spectra are analyzed by use of Fast Fourier Transforms to give an insight into the modulation mechanism. Two physical models, the electrical permittivity and the sheet conductivity which linearly vary as the electric field, are proposed to response for the transmittance modulation. The model-based simulations agree reasonable well with the experimental results.