Related papers: Large contrast enhancement of graphene monolayers …
We study the optical contrast for single and multilayer graphene deposited on a Au/SiO2/Si substrate. Our results prove that optical microscopy allows for easy and quick localization, identification and counting of graphene layers.…
The visibility of graphene sheets on different types of substrates has been investigated both theoretically and experimentally. Although single layer graphene is observable on various types of dielectrics under an optical microscope, it is…
We investigate graphene and graphene layers on different substrates by monochromatic and white-light confocal Rayleigh scattering microscopy. The image contrast depends sensitively on the dielectric properties of the sample as well as the…
A simple optical method is presented for identifying and measuring the effective optical properties of nanometer-thick, graphene-based materials, based on the use of substrates consisting of a thin dielectric layer on silicon. High contrast…
We show that it is possible to prepare and identify ultra--thin sheets of graphene on crystalline substrates such as SrTiO$_3$, TiO$_2$, Al$_2$O$_3$ and CaF$_2$ by standard techniques (mechanical exfoliation, optical and atomic force…
Microfabrication of graphene devices used in many experimental studies currently relies on the fact that graphene crystallites can be visualized using optical microscopy if prepared on top of silicon wafers with a certain thickness of…
We report a new method for quantitative estimation of graphene layer thicknesses using high contrast imaging of graphene films on insulating substrates with a scanning electron microscope. By detecting the attenuation of secondary electrons…
Imaging ellipsometry studies of graphene on SiO2/Si and crystalline GaAs are presented. We demonstrate that imaging ellipsometry is a powerful tool to detect and characterize graphene on any flat substrate. Variable angle spectroscopic…
We describe the identification of single- and few- layer boron nitride. Its optical contrast is much smaller than that of graphene but even monolayers are discernable by optimizing viewing conditions. Raman spectroscopy can be used to…
We model the optical visibility of monolayer and bilayer graphene deposited on a silicon/silicon oxide substrate or thermally annealed on the surface of silicon carbide. We consider reflection and transmission setups, and find that…
The ultimate surface exposure provided by graphene monolayer makes it the ideal sensor platform but also exposes its intrinsic properties to any environmental perturbations. In this work, we demonstrate that the charge carrier density of…
Monolayer graphene absorbs 2.3 percent of the incident visible light. This 'small' absorption has been used to emphasize the visual transparency of graphene, but it in fact means that multilayer graphene absorbs a sizable fraction of…
It was demonstrated that optical modulation together with simultaneous terahertz (THz) imaging application enables an increase in contrast by an order of magnitude illustrating hence the technique as convenient contactless tool for…
Gold is widely used as the substrate material in many graphene devices, due to its superior optoelectronic properties and chemical stability. However, there has been little experimental investigation on the optical contrast of graphene…
The field of two-dimensional materials has been developing at an impressive pace, with atomically thin crystals of an increasing number of different compounds that have become available, together with techniques enabling their assembly into…
We present the first experimental investigation of nonlinear optical properties of graphene flakes. We find that at near infrared frequencies a graphene monolayer exhibits a remarkably high third-order optical nonlinearity which is…
Identification of the mechanically exfoliated graphene flakes and classification of the thickness is important in the nanomanufacturing of next-generation materials and devices that overcome the bottleneck of Moore's Law. Currently,…
The magneto-optical absorption properties of graphene multilayers are theoretically studied. It is shown that the spectrum can be decomposed into sub-components effectively identical to the monolayer or bilayer graphene, allowing us to…
Materials can, in principle, be imaged at the level of individual atoms with aberration corrected transmission electron microscopy. However, such resolution can be attained only with very high electron doses. Consequently, radiation damage…
Optical reflection microscopy is one of the main imaging tools to visualize graphene microstructures. Here is reported a novel method that employs refractive index optimization in an optical reflection microscope, which greatly improves the…