Synthesis of Large-Scale Single-Crystalline Monolayer WS₂ Using a Semi-Sealed Method.

As a two-dimensional semiconductor, WS₂ has attracted great attention due to its rich physical properties and potential applications. However, it is still difficult to synthesize monolayer single-crystalline WS₂ at larger scale. Here, we report the growth of large-scale triangular single-crystalline WS₂ with a semi-sealed installation by chemical vapor deposition (CVD). Through this method, triangular single-crystalline WS₂ with an average length of more than 300 µm was obtained. The largest one was about 405 μm in length. WS₂ triangles with different sizes and thicknesses were analyzed by optical microscope and atomic force microscope (AFM). Their optical properties were evaluated by Raman and photoluminescence (PL) spectra. This report paves the way to fabricating large-scale single-crystalline monolayer WS₂, which is useful for the growth of high-quality WS₂ and its potential applications in the future.