RESUMO
MoSe2 is an attractive transition-metal dichalcogenide with a two-dimensional layered structure and various attractive properties. Although MoSe2 is a promising negative electrode material for electrochemical applications, further investigation of MoSe2 has been limited, mainly by the lack of MoSe2 mass-production methods. Here, we report a rapid and ultra-high-yield synthesis method of obtaining MoSe2 nanosheets with high crystallinity and large grains by ampoule-loaded chemical vapor deposition. Application of high pressure to an ampoule-type quartz tube containing MoO3 and Se powders initiated rapid reactions that produced vertically oriented MoSe2 nanosheets with grain sizes of up to â¼100 µm and yields of â¼15 mg h-1. Spectroscopy and microscopy characterizations confirmed the high crystallinity of the obtained MoSe2 nanosheets. Transistors and lithium-ion battery cells fabricated with the synthesized MoSe2 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 MoSe2.
RESUMO
Hexagonal molybdenum diselenide (MoSe2) multilayers were grown by chemical vapor deposition (CVD). A relatively high pressure (>760 Torr) was used during the CVD growth to achieve multilayers by creating multiple nuclei based on the two-dimensional crystal growth model. Our CVD-grown multilayer MoSe2 thin-film transistors (TFTs) show p-type-dominant ambipolar behaviors, which are attributed to the formation of Se vacancies generated at the decomposition temperature (650 °C) after the CVD growth for 10 min. Our MoSe2 TFT with a reasonably high field-effect mobility (10 cm(2)/V · s) exhibits a high photoresponsivity (93.7 A/W) and a fast photoresponse time (τ(rise) ~ 0.4 s) under the illumination of light, which demonstrates the practical feasibility of multilayer MoSe2 TFTs for photodetector applications.
