In the surge of recent successes of 2D materials following the rise of graphene, molybdenum disulfide (2D-MoS2) has been attracting growing attention from both fundamental and applications viewpoints, owing to the combination of its unique nanoscale properties. For instance, the bandgap of 2D-MoS2, which changes from direct (in the bulk form) to indirect for ultrathin films (few layers), offers new prospects for various applications in optoelectronics. In this review, we present the latest scientific advances in the field of synthesis and characterization of 2D-MoS2 films while highlighting some of their applications in energy harvesting, gas sensing, and plasmonic devices. A survey of the physical and chemical processing routes of 2D-MoS2 is presented first, followed by a detailed description and listing of the most relevant characterization techniques used to study the MoS2 nanomaterial as well as theoretical simulations of its interesting optical properties. Finally, the challenges related to the synthesis of high quality and fairly controllable MoS2 thin films are discussed along with their integration into novel functional devices.

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Molybdenum disulfide (MoS2) has been combined so far with other photodetecting semiconductors as an enhancing agent owing to its optical and electronic properties. Existing approaches demonstrated MoS2-incorporated photodetector devices using complex and costly fabrication processes. Here, we report on simplified one-step on the chemical vapor deposition (CVD) based synthesis of a unique microfiber/microflower MoS2-based heterostructure formed by capturing MoO2 intermediate material during the CVD process. This particular morphology engenders a material chemical and electronic interplay exalting the heterostructure absorption up to ~ 98% over a large spectral range between 200 and 1500 nm. An arsenal of characterization methods were used to elucidate the properties of these novel heterostructures including Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectrometry, high-resolution transmission and scanning electron microscopies, and Kelvin probe force microscopy. Our findings revealed that the MoS2 and the MoO2 crystallize in the hexagonal and monoclinic lattices, respectively. The integration of the MoS2/MoO2 heterostructures into functional photodetectors revealed a strong photoresponse under both standard sun illumination AM1.5G and blue light excitation at 450 nm. Responsivity and detectivity values as high as 0.75 mA W−1 and 1.45 × 107 Jones, respectively, were obtained with the lowest light intensity of 20 mW cm−2 at only 1 V bias. These results demonstrate the high performances achieved by the unique MoS2/MoO2 heterostructure for broadband light harvesting and pave the way for their adoption in photodetection applications.