da Silva M.F.P.,University of Sao Paulo |
de Oliveira D.R.,Institute Criminalistica Da Secretaria Of Seguranca Do Estado Of Sao Paulo |
de Oliveira D.R.,University of Sao Paulo |
Cavallari M.R.,University of Sao Paulo |
And 16 more authors.
Materials Chemistry and Physics | Year: 2015
A simple and efficient method for deposition of reduced graphene oxide (RGO) thin films onto arbitrary substrates is described. The present protocol consists in the application of radial compression to a thin layer of graphene oxide (GO) formed at the air-liquid interface of an ammoniacal dispersion of graphene oxide by continuous irradiation with visible light, that drives both the formation and curing of the film. Both infrared and near infrared luminescence spectroscopies were used for the proposition of a chemical mechanism in which the in situ singlet oxygen δ1O2, generated by the photosensitization of molecular oxygen to visible light, initiates the formation and curing of the film. The GO and RGO films display Raman spectral signatures typical of graphene - based materials, with thickness of ca. 20nm as evaluated by atomic force microscopy. The deposited films exhibited good transparency to visible light (max. 85%; 550±2nm), electrical resistivity equals to 14±0.02Ωm, sheet resistance equals to 5kΩsq-1 with associated charge carrier mobility of 200cm2/Vs. © 2015 Elsevier B.V.