Modified Spatially Confined Strategy Enabled Mild Growth Kinetics for Facile Growth Management of Atomically‐Thin Tungsten Disulfides

Abstract

Chemical vapor deposition (CVD) has been widely used to produce high quality 2D transitional metal dichalcogenides (2D TMDCs). However, violent evaporation and large diffusivity discrepancy of metal and chalcogen precursors at elevated temperatures often result in poor regulation on X:M molar ratio (M = Mo, W etc.; X = S, Se, and Te), and thus it is rather challenging to achieve the desired products of 2D TMDCs. Here, a modified spatially confined strategy (MSCS) is utilized to suppress the rising S vapor concentration between two aspectant substrates, upon which the lateral/vertical growth of 2D WS 2 can be selectively regulated via proper S:W zones correspond to greatly broadened time/growth windows. An S:W‐time (SW‐T) growth diagram was thus proposed as a mapping guide for the general understanding of CVD growth of 2D WS 2 and the design of growth routes for the desired 2D WS 2 . Consequently, a comprehensive growth management of atomically thin WS 2 is achieved, including the versatile controls of domain size, layer number, and lateral/vertical heterostructures (MoS 2 ‐WS 2 ). The lateral heterostructures show an enhanced hydrogen evolution reaction performance. This study advances the substantial understanding to the growth kinetics and provides an effective MSCS protocol for growth design and management of 2D TMDCs.

Large-area single-crystal TMD growth modulated by sapphire substrates

“…30 Wang et al used a modified space confinement strategy (MSCS) to greatly suppress the concentration of S vapor and reduce its concentration gradient on the substrate surface and achieve mild growth kinetics. 125 Oxide inhibitors can also be used to control the release of the metal source. Shi et al used SnO 2 to assist MoS 2 growth and Al 2 O 3 to assist MoSe 2 growth.…”