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

Abstract

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.