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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Making graphene visible on transparent dielectric substrates: Brewster angle imaging

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Romagnoli, Priscila [1] ; Rosa, Henrique G. [1] ; Lopez-Cortes, Daniel [1] ; Souza, Eunezio A. T. [1] ; Viana-Gomes, Jose C. [2] ; Margulis, Walter [3] ; de Matos, Christiano J. S. [1]
Total Authors: 7
[1] Univ Prebiteriana Mackenzie, MackGraphe Graphene & Nanomat Res Ctr, BR-01302907 Sao Paulo - Brazil
[2] Natl Univ Singapore, Ctr Adv Mat & Graphene Res Ctr 2D, Singapore 117542 - Singapore
[3] Acreo Swedish ICT AB, S-16440 Stockholm - Sweden
Total Affiliations: 3
Document type: Journal article
Source: 2D MATERIALS; v. 2, n. 3 SEP 2015.
Web of Science Citations: 6

The visibility of graphene is greatly increased by illuminating samples deposited on transparent dielectrics at the substrates' Brewster angle. Using a commercial ellipsometer, the reflectivity of monolayers of chemical vapour deposition (CVD) graphene is found to be up to 33 times higher than that of the substrate, i.e., an optical contrast as high as 3200% is obtained, more than 380 times higher than with standard optical microscopy. Also, with a simpler, homemade, experimental setup, a 1400% optical contrast was measured for a monolayer of CVD graphene and linear features as small as similar to 20 mu m were visible in a monolayer, while similar to 6 x 17 mu m(2) trilayers could still be imaged in exfoliated samples. It is also shown that the reflectance/transmittance ratio increases quadratically with the number of graphene layers, which may allow for counting layer numbers and identifying wrinkles and folds in transferred samples. (AU)

FAPESP's process: 12/50259-8 - Graphene: photonics and opto-electronics: UPM-NUS collaboration
Grantee:Antônio Hélio de Castro Neto
Support type: Research Projects - SPEC Program
FAPESP's process: 10/19085-8 - Study on optical properties of graphene and its aplication as saturable absorber in Erbium-doped fiber lasers
Grantee:Henrique Guimarães Rosa
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 12/07678-0 - Graphene fabrication and graphene doping for optical applications
Grantee:Henrique Guimarães Rosa
Support type: Scholarships abroad - Research Internship - Doctorate