Large area MoS2 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.