Reduced Defect Density in MOCVD-Grown MoS₂ by Manipulating the Precursor Phase

Advancements in the synthesis of large-area, high-quality two-dimensional transition metal dichalcogenides such as MoS 2 play a crucial role in the development of future electronic and optoelectronic devices. The presence of defects formed by sulfur vacancies in MoS 2 results in low photoluminescence emission and imparts high n-type doping behavior, thus substantially affecting material quality. Herein, we report a new method in which single-phase (liquid) precursors are used for the metal–organic chemical vapor deposition (MOCVD) growth of a MoS 2 film. Furthermore, we fabricated a high-performance photodetector (PD) and achieved improved photoresponsivity and faster photoresponse in the spectral range 405–637 nm compared to those of PDs fabricated by the conventional MOCVD method. In addition, the fabricated MoS 2 thin film showed a threshold voltage shift in the positive gate bias direction owing to the reduced number of S vacancy defects in the MoS 2 lattice. Thus, our method significantly improved the synthesis of monolayer MoS 2 and can expand the application scope of high-quality, atomically thin materials in large-scale electronic and optoelectronic devices.