Hydrogen-Assisted Growth of Large-Area Continuous Films of MoS₂ on Monolayer Graphene

We show how control over the chemical vapor deposition (CVD) reaction chemistry of molybdenum disulfide (MoS₂) by hydrogen addition can enable the direct growth of centimeter-scale continuous films of vertically stacked MoS₂ monolayer on graphene under atmospheric pressure conditions. Hydrogen addition enables longer CVD growth times at high temperature by reducing oxidation effects that would otherwise degrade the monolayer graphene. By careful control of nucleation density and growth time, high-quality monolayer MoS₂ films could be formed on graphene, realizing all CVD-grown vertically stacked monolayer semimetal/semiconducting interfaces. Photoluminescence spectroscopy shows quenching of MoS₂ by the underlying graphene, indicating a good interfacial charge transfer. We utilize the MoS₂/graphene vertical stacks as photodetectors, with photoresponsivities reaching 2.4 A/W under 135 μW 532 nm illumination. This approach provides insights into the scalable manufacturing of high-quality two-dimensional electronic and optoelectronic devices.