Correlating defect density with carrier mobility in large-scaled graphene films: Raman spectral signatures for the estimation of defect density

Abstract

We report a correlation between carrier mobility and defect density in large-scaled graphene films prepared by chemical vapor deposition (CVD). Raman spectroscopy is used for investigating the layer number and the crystal quality of graphene films, and the defect density is estimated by the intensity ratios of the D and G peaks. By carefully controlling the growth parameters, especially the H(2)/CH(4) ratios during growth, and employing H(2) during cooling, monolayer-dominant graphene films can be obtained with different D peak intensities in Raman spectra, which show good correspondence with their carrier mobility obtained by Hall measurements. Also, a progressive shift of neutrality points to a more negative gate voltage is observed with the increase in defect density. Both the connections of carrier mobility and the shift of neutrality points to a negative direction in relation to the defect density in graphene are observed for the first time in CVD-grown graphene films. With the best growth conditions, a cm-scaled graphene film with carrier mobility of ∼ 1350 cm(2) V(-1) s(-1) (p-type in air) can be obtained.

The ripple's enhancement in graphene sheets by spark plasma sintering

“…23,24 Figure 2(d) illustrates Raman spectra of the pristine and SPS treated graphenes. It has been known that there are three Raman peaks from graphene, that is, G peak at 1570 cm −1 , D peak at 1360 cm −1 , and 2D peak at 2720 cm −1 , and in general, the value of I d / I g reflects the surface defects density of graphene.…”

Variability Effects in Graphene: Challenges and Opportunities for Device Engineering and Applications

“…Artificially generated structural defects (e.g. ion irradiation) have been found to lower the mobility, shift the Dirac point, increase the noise and modify the transport properties [69,[169][170][171]. However, the quality of CVD-graphene has been significantly improved in recent years [17,23,172].…”

Non-covalent functionalization of CVD-grown graphene with Au nanoparticles for electrochemical sensing application

“…1, leading to the AuNPsanchored BDMT-modified graphene (AuNPs/BDMT/G) electrode. Large scale graphene film has been synthesized by using the conventional CVD route [37]. Functionalization of graphene has been carried out according to the following steps: the CVD-grown single layer graphene transferred on SiO 2 /Si wafer is first immersed in a 1 mM ethanolic solution of BDMT for 24 h under a nitrogensaturated condition, followed by washing with ethanol and drying under nitrogen flow.…”

“…Finally, the product is stored under vacuum. The detailed synthesis processes for the CVDgrown graphene [17,37] and AuNPs [38] are given in the supporting information.…”