Solvent effects on the drop cast films of few layers of MoS2 primed by facile exfoliation to realize optical and structural properties

MoS2, a two-dimensional (2D) layered material with variable bandgap and high stability, can be employed in optical and electronic applications due to its outstanding structural, electrical, and optical properties. The fabrication of MoS2 devices in a facile way is highly inevitable to minimize the time consumption and the cost due to its far-reaching and ceaseless applications. On behalf of their various applications, we have employed sonication-assisted liquid phase exfoliation of MoS2 followed by drop casting the sample in a glass plate for further characterization. MoS2 nanosheets were fabricated by exfoliating bulk MoS2 powder in different solvents with varying surface tension such as Ethanol, Ethylene Glycol (EG), Polyvinyl Pyrrolidone (PVP), Dimethylformamide (DMF), and Dimethyl Sulfoxide (DMSO). The structural and optical properties of the sample were analyzed using XRD, AFM, UV spectroscopy, photoluminescence (Pl) and Raman spectroscopy. The formation of 2D MoS2 film with (002) planes were identified and the thickness of the exfoliated nanosheets was confirmed to be in the nano regime. The optical properties of MoS2 revealed the existence of the spin-orbit coupling and the exciton-plasmon (plexitonic) coupling induced Rabi splitting in the Pl spectra, which increased with a reduction in layer number, and a negative correlation between Pl intensity and Rabi splitting is established. The variation in layer number of MoS2 on different solvents has been studied using the difference in Raman shift between E12g and A1g modes.