Shape Evolution of Monolayer MoS2 Crystals Grown by Chemical Vapor Deposition

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• 作者：Shanshan Wang ; Youmin Rong ; Ye Fan ; Merc猫 Pacios ; Harish Bhaskaran ; Kuang He ; Jamie H. Warner
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：November 25, 2014
• 年：2014
• 卷：26
• 期：22
• 页码：6371-6379
• 全文大小：675K
• ISSN：1520-5002

文摘

Atmospheric-pressure chemical vapor deposition (CVD) is used to grow monolayer MoS₂ two-dimensional crystals at elevated temperatures on silicon substrates with a 300 nm oxide layer. Our CVD reaction is hydrogen free, with the sulfur precursor placed in a furnace separate from the MoO₃ precursor to individually control their heating profiles and provide greater flexibility in the growth recipe. We intentionally establish a sharp gradient of MoO₃ precursor concentration on the growth substrate to explore its sensitivity to the resultant MoS₂ domain growth within a relatively uniform temperature range. We find that the shape of MoS₂ domains is highly dependent upon the spatial location on the silicon substrate, with variation from triangular to hexagonal geometries. The shape change of domains is attributed to local changes in the Mo:S ratio of precursors (1:>2, 1:2, and 1:<2) and its influence on the kinetic growth dynamics of edges. These results improve our understanding of the factors that influence the growth of MoS₂ domains and their shape evolution.