The GNR were fabricated on Si (high resistivity)/SiO2 substrates to facilitate transmission, by using EBL and Oxygen etching. The FTIR with transmission mode on 230nm ribbon array with parallel, perpendicular polarizations to the length of GNR as well as that with no polarizer are shown in the figure. I have used Si/SiO2 substrate as reference.
1) Assuming the peak at 1250cm-1 is the plasmonic response, I would expect a significant peak for perpendicular polarization than parallel. Any idea on this unexpected behavior?
2) Any explanation on the peak at 1750cm-1 for non polarized light?
3) Is it feasible to characterize plasmon resonance on GNR using FTIR reflection mode?
Suggestions towards troubleshooting these issues would be appreciated.
1. First of all, I am not sure about your test results because of the total transmission over 1 in long wavenumber for linear polarized incidence.
2. plasmon resonace on GNR can be obversed with both FTIR reflection and transmission measurments and field simulation with FEM or FDTD is a good way to characterize plasmon resonance or using SNOM in experiment directly.
3. Artifical nano structure based on graphene is one of my research, i propose a resonance peak of graphene nano slit with different Fermi energy to show the simulation result. i recommend you design the structure with simulation and than make the sample. if you want to know more about relevant simulation works, you can go to our website:http://phy.nankai.edu.cn/grzy/schen/English/publications.htm
4. Moreover, the crystal orientation need to be consided, Alpha-Si is recommended for substrate.
One more thing: Since the 1250 cm-1 peak is unpolarized I would think that this peak belongs to the SiO2 which was not properly removed by your reference.
Thanks Thomas, this peak should've shown polarization dependence if it's due to GNR resonance, so I suspect the substrate effects.
Thanks Zhancheng Li for your answer. I'll try the simulations. By the way, do you have any quantitative data on the correlation between quality of graphene (mobility) and the plasmonic resonance peak intensity? I think the the patterning using lithography as well as etching with oxygen might have considerably deteriorated the graphene.
Correlation between quality of graphene (mobility, alway 3000-10000 cm^2/Vs) and the plasmonic resonance peak intensity can be directily obtained with appropriate simulation model.
For experiment, the carrier concentration need to be measured to correspond Fermi energy in simulation.
Article Electric Field Effect in Atomically Thin Carbon Films
Article Dynamically Tunable Broadband Infrared Anomalous Refraction ...
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Carbon Materials
- Graphite
- Graphene