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Showing papers by "Cinzia Casiraghi published in 2011"


Journal ArticleDOI
TL;DR: In this paper, the shape of the bubble can be controlled by an external electric field, which can be used to make graphene-based adaptive focus lenses, and the effect of the electric field on the bubble shape is shown.
Abstract: Raised above the substrate and elastically deformed areas of graphene in the form of bubbles are found on different substrates. They come in a variety of shapes, including those which allow strong modification of the electronic properties of graphene. We show that the shape of the bubble can be controlled by an external electric field. This effect can be used to make graphene-based adaptive focus lenses.

192 citations


Journal ArticleDOI
12 Oct 2011-ACS Nano
TL;DR: In this article, the electrochemical properties of exfoliated single and multilayer graphene flakes were investigated using conductive silver paint and silver wires to fabricate contacts; epoxy resin was employed as a masking coating in order to expose a stable, well defined area of graphene.
Abstract: Results of a study on the electrochemical properties of exfoliated single and multilayer graphene flakes are presented. Graphene flakes were deposited on silicon/silicon oxide wafers to enable fast and accurate characterization by optical microscopy and Raman spectroscopy. Conductive silver paint and silver wires were used to fabricate contacts; epoxy resin was employed as a masking coating in order to expose a stable, well-defined area of graphene. Both multilayer and monolayer graphene microelectrodes showed quasi-reversible behavior during voltammetric measurements in potassium ferricyanide. However, the standard heterogeneous charge transfer rate constant, k°, was estimated to be higher for monolayer graphene flakes.

134 citations


Journal ArticleDOI
TL;DR: Both multilayer and monolayer graphene microelectrodes showed quasi-reversible behavior during voltammetric measurements in potassium ferricyanide, however, the standard heterogeneous charge transfer rate constant, k°, was estimated to be higher for monolayers graphene flakes.
Abstract: Results of a study on the electrochemical properties of exfoliated single and multilayer graphene flakes are presented. Graphene flakes were deposited on silicon/silicon oxide wafers to enable fast and accurate characterization by optical microscopy and Raman spectroscopy. Conductive silver paint and silver wires were used to fabricate contacts; epoxy resin was employed as masking coating in order to expose a stable, well defined area of graphene. Both multilayer and monolayer graphene microelectrodes showed quasi-reversible behavior during voltammetric measurements in potassium ferricyanide. However, the standard heterogeneous charge transfer rate constant, k{\deg}, was estimated to be higher for mono-layer graphene flakes.

122 citations


Journal ArticleDOI
13 Sep 2011-ACS Nano
TL;DR: Large-yield production of graphene flakes on glass by anodic bonding and it is shown that it is possible to easily transfer the flakes by the wedging technique, and the transfer on silicon does not damage graphene and lowers the doping.
Abstract: We report large-yield production of graphene flakes on glass by anodic bonding. Under optimum conditions, we counted several tens of flakes with lateral size around 20-30 mu m and a few tens of flakes with larger size. About 60-70% of the flakes have a negligible D peak. We show that it is possible to easily transfer the flakes by the wedging technique. The transfer on silicon does not damage graphene and lowers the doping. The charge mobility of the transferred flakes on silicon is on the order of 6000 cm(2)/V s (at a carrier concentration of 10(12) cm(-2)), which is typical for devices prepared on this substrate with exfoliated graphene.

48 citations


Journal ArticleDOI
TL;DR: In this article, a detailed analysis of the dependence of the Raman intensity of graphene on doping and disorder is presented, where the authors measured the total electron-phonon scattering rate in the framework of a fully resonant process.
Abstract: The Raman scattering process in graphene is always resonant, i.e. involves real electronic states, and this affects the Raman intensity. Thus, a detailed analysis of the Raman intensity of graphene can provide useful information on the Raman scattering process itself, in particular on the interaction between the fundamental excitations in graphene, such as electron–phonon and electron-defect interactions, which can be studied only by transport or complex techniques. Here a detailed analysis of the dependence of the Raman intensity of graphene on doping and disorder is presented. While the intensity of the G peak, I(G), is not strongly affected by small amount of doping or disorder, the intensity of the 2D peak strongly decreases with increasing doping or disorder. By analyzing the dependence of I(2D) with doping in the framework of a fully resonant process, we measured the total electron–phonon scattering rate.

31 citations


Journal ArticleDOI
TL;DR: A detailed analysis of the G and D peak Raman intensity of hydrogenated diamond-like carbon (DLC) with hydrogen (H) content ranging from 25 to 50 at% was presented in this paper.

15 citations


Journal ArticleDOI
TL;DR: In this article, a large-yield production of graphene flakes on glass by anodic bonding was reported, and the charge mobility of the transferred flakes on silicon was of the order of 6000 cm^2/V s (at carrier concentration of 10^12 cm^-2), which is typical for devices prepared on this substrate with exfoliated graphene.
Abstract: We report large-yield production of graphene flakes on glass by anodic bonding. Under optimum conditions, we counted several tens of flakes with lateral size around 20-30 {\mu}m and few tens of flakes with larger size. 60-70% of the flakes have negligible D peak. We show that it is possible to easily transfer the flakes by wedging technique. The transfer on silicon does not damage graphene and lowers the doping. The charge mobility of the transferred flakes on silicon is of the order of 6000 cm^2/V s (at carrier concentration of 10^12 cm^-2), which is typical for devices prepared on this substrate with exfoliated graphene.