Synthesis of highly dense MoO/MoS core-shell nanoparticles via chemical vapor deposition.

Nanostructure morphologies of transition metal dichalcogenides (TMDs) are gaining much interest owing to their catalytic, sensing, and energy storage capabilities. Here, we report the synthesis of highly dense MoO/MoS core-shell nanoparticles, a new form of TMD nanostructure, via chemical vapor deposition using new growth geometry where a thin film of MoO was used as a source substrate for Mo as opposed to using MoO powder used in conventional studies. To grow the MoO/MoS core-shell nanoparticles, we precisely control the carrier gas flow rate and sulfur vapor introduction time with respect to the melting of a MoO thin film used for Mo precursor.

Scalable lateral heterojunction by chemical doping of 2D TMD thin films.

Scalable heterojunctions based on two-dimensional transitional metal dichalcogenides are of great importance for their applications in the next generation of electronic and optoelectronic devices. However, reliable techniques for the fabrication of such heterojunctions are still at its infancy. Here we demonstrate a simple technique for the scalable fabrication of lateral heterojunctions via selective chemical doping of TMD thin films.

Uniform Vapor-Pressure-Based Chemical Vapor Deposition Growth of MoS Using MoO Thin Film as a Precursor for Coevaporation.

Chemical vapor deposition (CVD) is a powerful method employed for high-quality monolayer crystal growth of 2D transition metal dichalcogenides with much effort invested toward improving the growth process. Here, we report a novel method for CVD-based growth of monolayer molybdenum disulfide (MoS) by using thermally evaporated thin films of molybdenum trioxide (MoO) as the molybdenum (Mo) source for coevaporation. Uniform evaporation rate of MoO thin films provides uniform Mo vapors which promote highly reproducible single-crystal growth of MoS throughout the substrate.