Graphene

As one of the most durable, flexible and conductive 2D materials, Graphene continues to be studied and applied across multiple areas of research and industries. With applications in the energy sector, biomedical advances, electronics, and more, graphene remains a critical focus of research for both theoretical and applied scientists. 

Nanonics Multiprobe SPM Systems enable thermal, electrical, and optical transport studies on graphene and other 2D materials. Photoconductivity, AFM, Raman and TERS, as well as SNOM/NSOM measurements, are all available in a variety of environments within the same platform.

Methods

AFM Raman

Integrate AFM topography with Raman spectroscopy in one overlaid map.

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AFM image of graphene flake

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Raman spectra map of graphene flake

The image on the left is a 10um x 10um AFM height image of a graphene flake showing 2 distinct areas.

The graph on the right depicts Raman spectra collected from the different areas, clearly differentiating the region of the single layer (red spectrum) and the double layer (blue spectrum.) 

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AFM-Raman map of 2676cm-1 single layer band

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AFM-Raman map of the 2700cm-1 double layer band

Raman intensity has been overlaid on top of the AFM 3D topography, where red shows the highest Raman intensity and green shows the lowest Raman intensity [blue coloring corresponds to region without any graphene].

On the left is the AFM-Raman map of the 2676cm-1 single layer band, showing highest distribution of the single layer in the triangular red zone in the top half of the image.

On the right is the AFM-Raman map of the 2700cm-1 double layer band, showing the strongest signal in the top trapezoidal and bottom rectangular orange regions.

Note that the single and double layer band regions are located in different areas of the surface and are easily identified using the Raman maps.

TERS

Identify enhanced band of Graphene with TERS difference mapping.

Graphene AFM

AFM image of Graphene

Graphene Raman

Raman/TERS/Difference Graph - point (a)

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Raman/TERS/Difference Graph - point (b)

The image on the left is an AFM image of graphene. 

In the two corresponding graphs, both far-field Raman (black), TERS (red), and difference (green) spectra have been collected at two different spots on the surface.

Spectra in the center graph were collected at point (a) revealing a single layer of graphene.

Spectra in the graph on the right, collected at point (b), reveal a double layer of graphene.

This kind of difference mapping helps to identify the enhanced band only.

AFM Thermal Conductivity

Study in-situ AFM and thermal conductivity measurements.

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AFM (left) and Overlaid AFM/Thermal imaging (right) of graphene flakes

These images demonstrate in-situ AFM and thermal conductivity measurements 

AFM Kelvin Probe

Study in-situ AFM and Kelvin probe measurements.

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AFM (left) and KPM (right) images of graphene transistor with opposite voltage bias

These images demonstrate in-situ AFM and Kelvin probe measurements 

Photoconductivity

Obtain photocurrent images as a function of voltage without far-field background.

PV Graphene

Photoconductive image of a graphene transistor 

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Photoconductive images

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Diagram

Photocurrent images of a graphene transistor as a function of voltage without far-field background, using nanometric confinement of illumination in X Y and Z with apertured NSOM

Reference: Super-resolution Imaging of Photocurrent Induced in Graphene Transistor by Near-field Optical Excitation 

Mueller, T., Xia, F., Freitag, M., Tsang, J., & Avouris, P.

 Physical Review B, 79(24), 245430.  

6. Conductive AFM

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AFM image of graphene

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Raman spectra map of graphene

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Current graph of graphene

Multiprobe conductive AFM characterization with on-line monitoring of current and the 2D Raman scattering band of graphene.

Publications

 

Local hole doping concentration modulation on graphene probed by tip-enhanced Raman spectroscopy
Iwasaki, T., Zelai, T., Ye, S., Tsuchiya, Y., Chong, H. M., & Mizuta, H
Carbon 111 (2017): 67-73.

 

Quantifying Defect Densities in Monolayer Graphene Using Near-field Coherence Measurements.
Naraghi, R. R., Cançado, L. G., Salazar-Bloise, F., & Dogariu, A.
Frontiers in Optics, pp. FF5B-3. Optical Society of America, 2016.

 

Sn–and SnO 2–graphene flexible foams suitable as binder-free anodes for lithium ion batteries.
Botas, Cristina, Daniel Carriazo, Gurpreet Singh, and Teófilo Rojo.
Journal of Materials Chemistry A 3, no. 25 (2015): 13402-13410.

 

Enhanced graphene photodetector with fractal metasurface
Fang, Jieran, Di Wang, Clayton T. DeVault, Ting-Fung Chung, Yong P. Chen, Alexandra Boltasseva, Vladimir M. Shalaev, and Alexander V. Kildishev.
Nano letters 17, no. 1 (2016): 57-62.

Configurations

Which Nanonics system configuration is right for your Graphene research?