The peak positions of G band of suspended and supported

graphene are around 1,575 and 1,577 cm-1, and the I 2D/I G learn more ratios of suspended and supported graphene are around 3.9 and 2.1. The upshift of the G band reflects doping with charged impurities. The peak position of the G band of the suspended this website graphene is redshifted comparing to that of supported graphene, consistent with the above expectations. Figure 2 Peak positions of G band and I 2D / I G ratios by integrating their respect band. (a) Raman positions of G band and (b) I 2D/I G ratios of the probed area by scanning the mapping points on suspended graphene (c) shows the line mapping parameter. The examination on G-band peak positions and the I 2D/I G ratios for monolayer graphene flake covering on different substrates can provide information of substrate effect. In the previous reviews, the bandwidths of G and 2D bands were usually fitted by Lorentzian function [26–29], because it just related to the lifetime broadening between the levels. However, the bandwidth broadening of G bands was clearly observed and deserved worth to be investigated. Here, we introduced that the Voigt profile,

a convolution of a Lorentzian and a Gaussian, is suitable for fitting the transition linewidth and expressed [30–32] as (1) where the Gaussian profile and Lorentzian profile are expressed as G(ω, γ) and L(ω, Γ), and γ and Γ are their bandwidths.

In Figure 3a, the typical Raman spectrum (black line) of graphene was shown with the Lorentzian-fitted profile (blue line) and the Voigt-fitted profile (red line). C59 wnt price The related fitting parameter of the Raman spectrum was showed in Figure 3b. Figure 3 The Raman spectrum of graphene and the related fitting parameter of the Raman spectra. (a) The Raman spectrum (black line) of graphene, the Lorentzian-fitted profile (blue line), and the Voigt-fitted profile (red line). (b) The related fitting parameter of the Raman spectra. The bandwidth of Raman band was usually fitted and understood the situation of background of material by Gaussian function. Therefore, the G bands of supported and suspended graphene were fitted by Voigt profiles that give the Gaussian Casein kinase 1 and Lorentzian profiles. The fitting results of Raman spectra of supported (x = 0.5 μm) and suspended (x = 4.5 μm) graphene by Voigt profile are shown in Figure 4a,b. Figure 4 Raman spectra (black line) of (a) supported and (b) suspended graphene fitted by Voigt function (red line). Results and discussion Based on the data fitting results, the analysis of measured point across the graphene surface, the bandwidths of Gaussian profiles and Lorentzian profiles given by Voigt fitting is presented in Figure 4a,b. The horizontal axis is expressed as the mapping points of the area which contains supported (edge area) and suspended graphene (center area).