[Raman Application] Distribution of Graphene layer
Raman spectrometer can be used to distinguish single/multi layer of Graphene.
This sample is not single layer Graphene. We can use mapping function of Raman spectrometer to see the distribution of Graphene layer in an area.
1. Mapping: From the mapping image it is possible to highlight that the sample does not correspond to mono-layer Graphene, as the changes of the signal on the image shows the distribution of the different layers .
2. Sample structure: Graphene sample was prepared by CVD process, using low pressure and high temperature (1173~1273K). When the Graphene structure is not meticulous, defects on it cause the heat accumulate on it, so Graphene quench easily. The structure of Layered Graphene is more integrated than powder Graphene therefore power Graphene quench easier For more integrated than powder Graphene, therefore power Graphene quench easier. For the same reason in general monolayer Graphene is the most accepted, this sample is the result of a CVD process, If when the first layer is completed, there is a gap between the first layer and the substrate, in this case the reaction is not fully completed, Carbon atoms forming a second layer is deposited into the gap, and so on the third layer will form.
3. Single-point spectrum: MRI532 mapping system can clearly measure Graphene peaks as G-band ≈ 1580 cm-1, G'-band ≈ 2700 cm-1, D-band ≈ 1350 cm-1 and other peaks.
In addition, MRI532 system clearly points distinguish D'-band = 1620 cm-1 aprox.