Institut des
NanoSciences de Paris
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Research

Those research topics were developed in close collaborations with various groups worldwide : Yves J. Chabal (University of Texas at Dallas), Philippe Dollfus (Université Paris-Sud), Miquel Salmeron (University of California Berkeley), A-F Lamic-Humblot (chemistry department at UPMC), Sergii Snegir (Kyiv University), François Rochet (chemistry department at UPMC), Thomas Huhn (University of Konstanz, chemistry department), Elke Scheer (University of Konstanz, physics department), Bertrand Busson (University of Paris-Saclay)


(1) Charge transport in hybrid systems and molecular electronics : metallic nanoparticles, molecules, semiconductor

Charge transport in hybrid systems and molecular electronics. We are interested in understanding how electric charges are driven through molecules and molecular systems. Molecules are self-assembled into monolayers on surfaces or are connected to individual nanoparticles. We have especially studied the case of Grafted Organic Monolayers (GOM) on oxide-free silicon and have developed an electric model that takes into account the band bending of the substrate. This allows predicting the electrostatics of hybrid systems silicon-molecule-gold nanoparticle.

The number of charges stored by individual nanoparticles was measured in air with KPFM (Kelvin Probe Force Microscopy). Our group has recently purchased a state-of-the-art KPFM (2015). Currently we investigate how the nature of molecules capping gold nanoparticles modifies their electrical properties (work function, charge state).


(2) Nanoelectronics, single charge electronics with gold nanoparticles

Go-N-SEE project : Gold Nanoparticles for Single Electron Experiments

Gold nanoparticles serve as ultra-small electron dispensers and make possible the control of electric current with the accuracy of a single electron (Coulomb blockade). The challenge is to fabricate reproducible architectures where gold nanoparticles of diameters between 5 and 10 nm are deposited on top of a GOM molecular layer which plays the role of an insulating layer (tunnel barrier) and which is grafted on a silicon substrate. The experimental study is carried out in ultra-high vacuum with a STM (Scanning Tunnel Microscope).

Read a 3 pages summary published in SPIE Newsroom. Gold nanoparticles to drive single-electron currents


(3) Plasmonics in gold nanoparticles and its relation to electron transfer.

Plasmo-PIX project : plasmonics for a new pixels technology

Gold nanoparticles exhibit unique optical properties related to their plasmon resonance (LSPR). Our research focuses on the way to tune this plasmon resonance by using charge transfer and molecular attachment. We are specially working with switchable molecules such as diarylethene molecules whose morphology and electronics properties can be switched by illumination at the proper wavelength.


(4) Former topic : molecular reactivity on surfaces.

We have investigated the mechanism at play when a chemical bond is created between a silicon substrate and some organic molecules (see video 2 « Adsorption of the phenylacetylene », on the video page).Thanks to a tight collaboration with Y. J Chabal at University of Texas at Dallas, we have developed the Grafted Organic Monolayers (GOM) where molecules are bound covalently directly to silicon without no oxide layer. This GOM offers unique electrical properties.


(5) Former topic : Plasmonics, linear and nonlinear optical response of gold nanoparticles.

I am interested in understanding how the optical properties due to the plasmon resonance can be used to enhance the sensitivity of nanoparticles to their molecular environment and make them ultra sensitive nano-sensors. The optical probe of the molecules was achieve with Sum Frequency Generation a nonlinear optical spectroscopy. This research was developped in close collaboration with B. Busson and C. Humbert at CLIO-LCP laboratory (University Paris-Saclay).


Highlights published on INSP website (in French) / Faits d’actualités publiés sur le site de l’INSP