Scalable faceted voids with luminescent enhanced edges in WS2 monolayers

Pawan Kumar, Dipanwita Chatterjee, Takuya Maeda, Ahin Roy, Kenji Kaneko, Viswanath Balakrishnan

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

A scalable approach is needed in the formation of atomically flat edges with specific terminations to enhance local properties for optoelectronic, nanophotonic and energy applications. We demonstrate point defect clustering-driven faceted void formations with luminescent enhanced edges in WS2 monolayers during large-scale CVD growth and controlled annealing. With the aid of aberration-corrected scanning transmission electron microscopy (AC-STEM) high angle annular dark field (HAADF) imaging, we probed atomic terminations of S and W to explain observed luminescence enhancement in alternate edges. Faceted void formation in monolayer WS2 was found to be sensitive to annealing temperature, time, gas environment and precursor supply. Our observations of areal coverage evolution over time revealed competition between monolayer WS2 growth and void formation at 850 °C. While the initial stage was dominated by monolayer growth, defect generation and void growth dominated at later stages and provided an optimum processing window for monolayer WS2 as well as faceted void growth. Growth of faceted voids not only followed the geometry of monolayer facets but also showed similar atomic terminations at the edges and thus enabled local manipulation of photoluminescence enhancement with an order of magnitude increase in intensity. The developed CVD processing enabled multi-fold increase in the luminescent active edge length through the formation of faceted voids within the WS2 monolayer.

Original languageEnglish
Pages (from-to)16321-16331
Number of pages11
JournalNanoscale
Volume10
Issue number34
DOIs
Publication statusPublished - Sep 14 2018

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Monolayers
Chemical vapor deposition
Annealing
Nanophotonics
Point defects
Processing
Aberrations
Optoelectronic devices
Luminescence
Photoluminescence
Gases
Transmission electron microscopy
Imaging techniques
Defects
Scanning electron microscopy
Geometry
Temperature

All Science Journal Classification (ASJC) codes

  • Materials Science(all)

Cite this

Kumar, P., Chatterjee, D., Maeda, T., Roy, A., Kaneko, K., & Balakrishnan, V. (2018). Scalable faceted voids with luminescent enhanced edges in WS2 monolayers. Nanoscale, 10(34), 16321-16331. https://doi.org/10.1039/c8nr02246a

Scalable faceted voids with luminescent enhanced edges in WS2 monolayers. / Kumar, Pawan; Chatterjee, Dipanwita; Maeda, Takuya; Roy, Ahin; Kaneko, Kenji; Balakrishnan, Viswanath.

In: Nanoscale, Vol. 10, No. 34, 14.09.2018, p. 16321-16331.

Research output: Contribution to journalArticle

Kumar, P, Chatterjee, D, Maeda, T, Roy, A, Kaneko, K & Balakrishnan, V 2018, 'Scalable faceted voids with luminescent enhanced edges in WS2 monolayers', Nanoscale, vol. 10, no. 34, pp. 16321-16331. https://doi.org/10.1039/c8nr02246a
Kumar P, Chatterjee D, Maeda T, Roy A, Kaneko K, Balakrishnan V. Scalable faceted voids with luminescent enhanced edges in WS2 monolayers. Nanoscale. 2018 Sep 14;10(34):16321-16331. https://doi.org/10.1039/c8nr02246a
Kumar, Pawan ; Chatterjee, Dipanwita ; Maeda, Takuya ; Roy, Ahin ; Kaneko, Kenji ; Balakrishnan, Viswanath. / Scalable faceted voids with luminescent enhanced edges in WS2 monolayers. In: Nanoscale. 2018 ; Vol. 10, No. 34. pp. 16321-16331.
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