Photoluminescence Enhancement Effect of the Layered MoS₂ Film Grown by CVD

Abstract

The layered MoS 2 films have been prepared by the chemical vapor deposition (CVD) method, which shows numerous MoS 2 convex flakes (i.e., MoS 2 nanosheets) on SiO 2 /Si substrates. The convex flake islands form a uniform layered film and the single flake corresponds to one small piece of monolayer MoS 2 film; they show a strong photoluminescence (PL) radiation as a whole. The thickness of the layered MoS 2 films increases with the increases of growth time, the effect of diverse growth time on the properties of layered MoS 2 films has been discussed, and the PL enhancement effect is due to the PL intensity accumulation from each of the convex flakes. The strong PL radiation has been found by annealing the samples and the reason has been analyzed. The layered MoS 2 films could provide more photon energy than both the monolayer MoS 2 film and the bulk MoS 2 . This work provides a fundamental study about the device fabrication based on layered MoS 2 films. The optoelectronic devices based on this study will be more energy efficient.