Context :
Carbon nanotubes (CNTs) possess extraordinary mechanical, thermal, and electrical properties due to their structure and sp2-hybridization, which brings to powerful charge transport. Single-wall CNTs (SWCNTs) can be supposed as the best material to confine water molecules because of their high aspect ratio, hydrophobic interior, etc. The static (structure and phase) and dynamic (transport) properties of water confined in the nanoscale is different from bulk water [1].
Even though the effect of the humidity outside the SWCNT network is known [2], it is challenging to carry out experiments with individual SWCNT to get insights into the effect of water confined inside the tube. SWCNT field effect transistors (SWCNT-FET) showed that the electronic properties of SWCNTs are sensitive to their diameter, defects, doping, adsorbates, and environment [3].
This work will be the ongoing part of the current work, where we distinguish electrically the effect of the water confined inside individual SWCNT from that adsorbed outside. The change of gate threshold voltage, current, and slope based on the possiblemechanism, Schottky barrier effect in the metal-NT contact, band structure of the NT, doping, and mobility will thus be investigated [4].
Furthermore, the effect of water molecules outside and inside of the individual CNT will be distinguished optically using Raman spectroscopy. In this process, the effect will be observed with the change of the corresponding Raman bands of the individual SWCNT with adsorbed or confined molecules.
This work will open perspectives to combine nonfluidic and nanoelectronics in one device, for using CNTFET as for instance as reliable, selective, and sensitive chemical and biological sensor application.

[1] T. A. Pascal et al., Proc. Natl. Acad. Sci. U.S.A., 108, 11794-11798 (2011)
[2] P. S. Na et al., Appl. Phys. Lett., 87, 10-13 (2003)
[3] D. Cao et al., ACS Nano., 5, 3113-3119 (2011)
[4] I. Heller et al., Nano Lett., 8, 591-595 (2008)

Scientific and technical work :
The internship aims at optically characterizing the properties of individual SWCNT to distinguish confined water from adsorbed water. The project will involve experimental techniques such as Raman scattering, electrical probe station, clean room techniques and computer analysis tools.
In this project the student will :

• Learn and perform photolithography of samples (clean room work)
• Learn and use Raman scattering to probe the properties of carbon nanotubes
• Learn and use a probe station with SMU (Source Measure Unit)
• Analyze the experimental data by mean of software or computer language (Origin, MATLAB, Python…)
• Synthetize the obtained results for discussing them with the consortium of researchers involved

If needed, the student may :
– Prepare new catalyst for the growth of nanotubes (chemistry steps, basic level)

Profile :
This project is adapted for a student with a background in physics, applied physics, nanoscience or chemical physics. The internship involves substantial experimental work, so the motivation for experimental work is mandatory. Strong desire for interdisciplinary research and learning is also essential.

Additional information :
Length of internship : 4-6 months
Starting date : flexible
The student will receive a grant of : 500€/month
Website : https://nanomechanics.fr/

Advisor : Adrien Noury