Continuous Large Area Monolayered Molybdenum Disulfide Growth Using Atmospheric Pressure Chemical Vapor Deposition

The growth of large crystallite continuous monolayer materials like molybdenum disulfide (MoS₂) with the desired morphology via chemical vapor deposition (CVD) remains a challenge. In CVD, the complex interplay of various factors like growth temperatures, precursors, and nature of the substrate decides the crystallinity, crystallite size, and coverage area of the grown MoS₂ monolayer. In the present work, we report about the role of weight fraction of molybdenum trioxide (MoO₃), sulfur, and carrier gas flow rate toward nucleation and monolayer growth. The concentration of MoO₃ weight fraction has been found to govern the self-seeding process and decides the density of nucleation sites affecting the morphology and coverage area. A carrier gas flow of 100 sccm argon results in large crystallite continuous films with a lower coverage area (70%), while a flow rate of 150 sccm results in 92% coverage area with a reduced crystallite size. Through a systematic variation of experimental parameters, we have established the recipe for the growth of large crystallite atomically thin MoS₂ suitable for optoelectronic devices.