Raman Spectroscopy Characterization of Graphene & Graphene Oxide

Raman Spectroscopy Characterization of Graphene & Graphene Oxide
Raman Spectroscopy is the best technique for the qualitative analysis of the Graphene.
Single, Double, Few & Multi Layer Graphene can be determined by the: Peak Position, Peak Intensity and Peak Broadening of the Raman Spectra. Ideal Raman Spectra for Graphene is given below:


NUMBER OF LAYERS CALCULATOR: There are mainly these THREE methods, which can be used to calculate the number of layers in Graphene by Raman Spectroscopy: Method1: G Band Position in Raman Spectra; Method 2: Intensity Ratio of 2D:G Peak in Raman Spectra; Method 3: Intensity Ratio of D:G Peak in Raman Spectra

G Band Intensity

D Band Intensity

2D Band Intensity

Results

ID/IG Ratio

I2D/IG Ratio


THEORY BEHIND CALCULATIONS:
FOR METHOD1: Calculations are based on the following relation (532nm LASER): wG = 1581.6 + 11/(1 + n^1.6) Where wG = G Band Position in Raman Spectra; n = Number of layers Raman of Graphene

FOR METHOD2: (Most Reliable) Calculations are based on the Literature Surveys done regarding the Intensity ratio of 2D:G peak in Raman Spectra.

FOR METHOD3: Calculations are based on the Literature Surveys done regarding the Intensity ratio of D:G peak in Raman Spectra. Toggle panel: Yoast SEO Toggle panel: Custom appearance in Grid Thank you for creating with WordPress. Version 5.1.1

8 comments:

  1. Really you are trying life simple. You made me to have clear picture about the concept.

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  2. Can you suggest us references for supporting the explanation, please?

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  3. Siva Reddy Kasireddy23 August 2017 at 12:39

    Insta NANO is highly useful for me in clearing my doubts.

    Thanks.

    ReplyDelete
  4. Care must be taken with the first method, G band peak position. There need to be not strain present as that will shift the peak to lower wavenumber and any presence of doping will also influence the peak position.
    Method 2) 2D:G band ratio will give a good indication of single layer graphene with the ratio being around 2 or higher. The band shape however may distort the shape of the 2D band causing broadening. This is particularly evident for Bernal stacking of layers that is seen in HOPG graphene that has been exfoliated. In regards to CVD grown graphene the 2D:G may be more appropriate.
    I have seen that exfoliated Graphene layer thickness follows a linear trend in G band intensity at upto 19 layers presenting a very good way to determine layer thickness for those samples. Here is a link to an application note I authored on the topic:
    https://tools.thermofisher.com/content/sfs/brochures/AN52252_E%201111%20LayerThkns_H_1.pdf
    By the way, the figure in method 1 was taken from my work

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  5. if we don't have a 2d peak in raman can we still get the graphene or 2d is compulsory condition for graphene

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  6. 2D band is not necessary for Graphene Oxide

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  7. 2D band necessery to call it as a graphene or 2 dimensional resonance accord.
    Please do correct me if I am wrong..

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  8. How can I determine the level of doping in a graphene from a Raman spectrum? What is exactly the formula I should use?

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