相关论文: Ultra-low doping and local charge variation in gra…

Avoiding charge density fluctuations and impurities in graphene is vital for high-quality graphene-based devices. Traditional characterization methods require device fabrication and electrical transport measurements, which are…

Accurate and simple local strain assessment in graphene is one of the crucial tasks in device characterization. Raman spectroscopy is often used for that purpose through monitoring of the G and 2D modes. However, the shifts of those two…

We report strong variations in the Raman spectra for different single-layer graphene samples obtained by micromechanical cleavage, which reveals the presence of excess charges, even in the absence of intentional doping. Doping…

Raman spectroscopy is a powerful tool for characterizing the local properties of graphene. Here, we introduce a method for evaluating unknown strain configurations and simultaneous doping. It relies on separating the effects of hydrostatic…

We present spatially resolved Raman images of the G and 2D lines of single-layer graphene flakes. The spatial fluctuations of G and 2D lines are correlated and are thus shown to be affiliated with local doping domains. We investigate the…

We demonstrate electrochemical top gating of graphene by using a solid polymer electrolyte. This allows to reach much higher electron and hole doping than standard back gating. In-situ Raman measurements monitor the doping. The G peak…

Since lattice strain and charge density affect various material properties of graphene, a reliable and efficient method is required for quantification of the two variables. While Raman spectroscopy is sensitive and non-destructive, its…

Raman spectroscopy, a fast and nondestructive imaging method, can be used to monitor the doping level in graphene devices. We fabricated chemical vapor deposition (CVD) grown graphene on atomically flat hexagonal boron nitride (hBN) flakes…

The Raman 2D line of graphene is widely used for device characterization and during device fabrication as it contains valuable information on e.g. the direction and magnitude of mechanical strain and doping. Here we present systematic…

Raman spectroscopy is one of the widely used methods in the analysis of various samples including carbon-based materials. This study aimed to identify the number of layers and defects in graphene using micro-Raman spectroscopy. More…

Raman spectroscopy of graphene is reviewed from a theoretical perspective. After an introduction of the building blocks (electronic band structure, phonon dispersion, electron-phonon interaction, electron-light coupling), Raman intensities…

Raman spectroscopy is a fast, non-destructive means to characterize graphene samples. In particular, the Raman spectra show a significant dependence on doping. While the change in position and width of the G peak can be explained by the…

We present low-temperature Raman measurements on gate tunable graphene encapsulated in hexagonal boron nitride, which allows to study in detail the Raman G and 2D mode frequencies and line widths as function of the charge carrier density.…

Here we use pristine graphene samples in order to analyze how the Raman peaks intensity, measured at 2.4 eV and 1.96 eV excitation energy, changes with the amount of doping. The use of pristine graphene allows investigating the intensity…

Graphene, due to its superior stretchability, exhibits rich structural deformation behaviors and its strain-engineering has proven useful in modifying its electronic and magnetic properties. Despite the strain-sensitivity of the Raman G and…

We investigated Raman spectra of single-layer and multi-layer graphene under ultraviolet laser excitation at the wavelength of 325 nm. It was found that while the G peak of graphene remains pronounced in UV Raman spectra, the 2D band…

We report a Raman spectroscopy study of graphene field-effect transistors (GFET) with a controlled amount of defects introduced in graphene by exposure to electron-beam irradiation. Raman spectra are taken at T = 8 K over a range of back…

We show the evolution of Raman spectra with number of graphene layers on different substrates, SiO$_{2}$/Si and conducting indium tin oxide (ITO) plate. The G mode peak position and the intensity ratio of G and 2D bands depend on the…

We study theoretically the Raman spectrum of the rotated double-layer graphene, consisting of two graphene layers rotated with respect to each other by an arbitrary angle \theta. We find a relatively simple dependence of the Raman G peak…

We investigate the evolution of the Raman spectrum of defected graphene as a function of doping. Polymer electrolyte gating allows us to move the Fermi level up to 0.7eV, as monitored by \textit{in-situ} Hall-effect measurements. For a…