Observing grain boundaries in CVD-grown monolayer transition metal dichalcogenides

Thuc Hue Ly, Ming Hui Chiu, Ming Yang Li, Jiong Zhao, David J. Perello, Magdalena Ola Cichocka, Hye Min Oh, Sang Hoon Chae, Hye Yun Jeong, Fei Yao, Lain Jong Li, Young Hee Lee

Research output: Journal article publicationJournal articleAcademic researchpeer-review

116 Citations (Scopus)


Two-dimensional monolayer transition metal dichalcogenides (TMdCs), driven by graphene science, revisit optical and electronic properties, which are markedly different from bulk characteristics. These properties are easily modified due to accessibility of all the atoms viable to ambient gases, and therefore, there is no guarantee that impurities and defects such as vacancies, grain boundaries, and wrinkles behave as those of ideal bulk. On the other hand, this could be advantageous in engineering such defects. Here, we report a method of observing grain boundary distribution of monolayer TMdCs by a selective oxidation. This was implemented by exposing directly the TMdC layer grown on sapphire without transfer to ultraviolet light irradiation under moisture-rich conditions. The generated oxygen and hydroxyl radicals selectively functionalized defective grain boundaries in TMdCs to provoke morphological changes at the boundary, where the grain boundary distribution was observed by atomic force microscopy and scanning electron microscopy. This paves the way toward the investigation of transport properties engineered by defects and grain boundaries. (Figure Presented).
Original languageEnglish
Pages (from-to)11401-11408
Number of pages8
JournalACS Nano
Issue number11
Publication statusPublished - 1 Jan 2014
Externally publishedYes


  • Atomic force microscopy
  • Sapphire grain boundary
  • Scanning electron microscopy
  • Selective oxidation
  • STEM
  • TEM
  • Transition metal dichalcogenides

ASJC Scopus subject areas

  • General Materials Science
  • General Engineering
  • General Physics and Astronomy


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