Two‐dimensional transition metal dichalcogenides (TMDs) hold great potential for future low‐energy optoelectronics owing to their unique electronic, optical, and mechanical properties. Chemical vapor deposition (CVD) is the technique widely used for the synthesis of large‐area TMDs. However, due to high sensitivity to the growth environment, reliable synthesis of monolayer TMDs via CVD remains challenging. Here a controllable CVD process is developed for large‐area synthesis of monolayer WS₂ crystals, films, and in‐plane graphene–WS₂ heterostructures by cleaning the reaction tube with hydrochloric acid, sulfuric acid, and aqua regia. The concise cleaning process can remove the residual contaminates attached to the CVD reaction tube and crucibles, reducing the nucleation density but enhancing the diffusion length of WS₂ species. The photoluminescence (PL) mappings of a WS₂ single crystal and film reveal that the extraordinary PL around the edges of a triangular single crystal is induced by ambient water intercalation at the WS₂–sapphire interface. The extraordinary PL can be controlled by the choice of substrates with different wettabilities.

中文翻译：

---

水嵌入诱导的大面积单层WS2单晶，薄膜和异质结构的可靠合成与非凡的光致发光

二维过渡金属二硫化碳（TMD）凭借其独特的电子，光学和机械性能，在未来的低能耗光电子学中具有巨大的潜力。化学气相沉积（CVD）是广泛用于合成大面积TMD的技术。然而，由于对生长环境的高度敏感性，通过CVD可靠地合成单层TMD仍然具有挑战性。这里开发了一种可控的CVD工艺，用于大面积合成单层WS ₂晶体，薄膜和面内石墨烯– WS ₂通过用盐酸，硫酸和王水清洗反应管来清除异质结构。简洁的清洁工艺可​​以去除附着在CVD反应管和坩埚上的残留污染物，降低成核密度，但增加WS ₂物质的扩散长度。WS ₂单晶和薄膜的光致发光（PL）映射表明，三角形单晶边缘周围的非常规PL是由WS _2-蓝宝石界面处的环境水嵌入引起的。可以通过选择具有不同润湿性的基材来控制非凡的PL。