Controllable Synthesis of Large-Scale Monolayer MoS₂ Dendritic Flakes with Serrated Edges and Their Multimodal Microscopy and AFM Characterizations

The controllable fabrication of high-yield and large-sized atomically thin MoS2 dendritic flakes is highly desirable for catalytic applications due to the abundant edge sites. Here, we present the synthesis of high-yield monolayer MoS2 dendritic flakes with serrated edges on a whole amorphous Si/SiO2 substrate by utilizing an ambient-pressure space-confined chemical vapor deposition (CVD) method. The two-dimensional (2D) monolayer MoS2 flakes were shown to exhibit a remarkable shape evolution from triangular flakes to dendritic flakes with serrated edges to triangular flakes with a few short branches, as well as size variations ranging from several micrometers to similar to 855 mu m, by tailoring the growth parameters. Optical and electrical characterizations proved the formation of grain boundaries in the dendritic flake obtained at high growth temperatures. Moreover, the growth mechanism of 2D MoS2 flakes was discussed based on the morphological evolution of 2D domains under diverse growth parameters. Our study paves a novel pathway to optimize the fabrication of 2D dendritic flakes and provides technical guidance for designing effective catalysts.