Making graphene visible on transparent dielectric substrates: Brewster angle imaging

Autor(es)

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]

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: 2D MATERIALS; v. 2, n. 3 SEP 2015.
• Citações Web of Science: 6

Resumo

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)

• Processo FAPESP: 10/19085-8 - Estudo das propriedades ópticas do grafeno e sua aplicação como absorvedor saturável em lasers à fibra dopada com érbio
• Beneficiário: Henrique Guimarães Rosa
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/07678-0 - Fabricação e dopagem de grafeno para aplicações em óptica
• Beneficiário: Henrique Guimarães Rosa
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 12/50259-8 - Grafeno: fotônica e opto-eletrônica: colaboração UPM-NUS
• Beneficiário: Antonio Helio de Castro Neto
• Modalidade de apoio: Auxílio à Pesquisa - Programa SPEC