Large area MoS(2) thin film growth by direct sulfurization

In this study, we present the growth of monolayer MoS(2) (molybdenum disulfide) film. Mo (molybdenum) film was formed on a sapphire substrate through e-beam evaporation, and triangular MoS(2) film was grown by direct sulfurization. First, the growth of MoS(2) was observed under an optical microscope. The number of MoS(2) layers was analyzed by Raman spectrum, atomic force microscope (AFM), and photoluminescence spectroscopy (PL) measurement. Different sapphire substrate regions have different growth conditions of MoS(2). The growth of MoS(2) is optimized by controlling the amount and location of precursors, adjusting the appropriate growing temperature and time, and establishing proper ventilation. Experimental results show the successful growth of a large-area single-layer MoS(2) on a sapphire substrate through direct sulfurization under a suitable environment. The thickness of the MoS(2) film determined by AFM measurement is about 0.73 nm. The peak difference between the Raman measurement shift of 386 and 405 cm(−1) is 19.1 cm(−1), and the peak of PL measurement is about 677 nm, which is converted into energy of 1.83 eV, which is the size of the direct energy gap of the MoS(2) thin film. The results verify the distribution of the number of grown layers. Based on the observation of the optical microscope (OM) images, MoS(2) continuously grows from a single layer of discretely distributed triangular single-crystal grains into a single-layer large-area MoS(2) film. This work provides a reference for growing MoS(2) in a large area. We expect to apply this structure to various heterojunctions, sensors, solar cells, and thin-film transistors.