Rapid and mass-producible synthesis of high-crystallinity MoSe nanosheets by ampoule-loaded chemical vapor deposition.

MoSe is an attractive transition-metal dichalcogenide with a two-dimensional layered structure and various attractive properties. Although MoSe is a promising negative electrode material for electrochemical applications, further investigation of MoSe has been limited, mainly by the lack of MoSe mass-production methods. Here, we report a rapid and ultra-high-yield synthesis method of obtaining MoSe nanosheets with high crystallinity and large grains by ampoule-loaded chemical vapor deposition. Application of high pressure to an ampoule-type quartz tube containing MoO and Se powders initiated rapid reactions that produced vertically oriented MoSe nanosheets with grain sizes of up to ∼100 μm and yields of ∼15 mg h. Spectroscopy and microscopy characterizations confirmed the high crystallinity of the obtained MoSe nanosheets. Transistors and lithium-ion battery cells fabricated with the synthesized MoSe nanosheets showed good performance, thereby further indicating their high quality. The proposed simple scalable synthesis method can pave the way for diverse electrical and electrochemical applications of MoSe.