Role of alkali metal promoter in enhancing lateral growth of monolayer transition metal dichalcogenides

Hyun Kim, Gang Hee Han, Seok Joon Yun, Jiong Zhao, Dong Hoon Keum, Hye Yun Jeong, Thuc Hue Ly, Youngjo Jin, Ji Hoon Park, Byoung Hee Moon, Sung Wng Kim, Young Hee Lee

Research output: Journal article publicationJournal articleAcademic researchpeer-review

28 Citations (Scopus)

Abstract

Synthesis of monolayer transition metal dichalcogenides (TMDs) via chemical vapor deposition relies on several factors such as precursor, promoter, substrate, and surface treatment of substrate. Among them, the use of promoter is crucial for obtaining uniform and large-area monolayer TMDs. Although promoters have been speculated to enhance adhesion of precursors to the substrate, their precise role in the growth mechanism has rarely been discussed. Here, we report the role of alkali metal promoter in growing monolayer TMDs. The growth occurred via the formation of sodium metal oxides which prevent the evaporation of metal precursor. Furthermore, the silicon oxide substrate helped to decrease the Gibbs free energy by forming sodium silicon oxide compounds. The resulting sodium metal oxide was anchored within such concavities created by corrosion of silicon oxide. Consequently, the wettability of the precursors to silicon oxide was improved, leading to enhance lateral growth of monolayer TMDs.
Original languageEnglish
Article number36LT01
JournalNanotechnology
Volume28
Issue number36
DOIs
Publication statusPublished - 8 Aug 2017
Externally publishedYes

Keywords

  • alkali metals
  • chemical vapor deposition
  • growth mechanism
  • promoters
  • transition metal dichalcogenides

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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