04/06/2019 Offres d'emploi

Offre de thèse/ Doctoral Position - INSP - 2019

Thesis on Electrically connected gold nanoparticles for molecular switches

Context: All informations inside the pdf

This PhD work is proposed in the framework of a successful international funding granted by the ANR (Agence Nationale de la Recherche) and the DFG (Deutsche Forschung Gemeinschaft, Germany). The project name is PlasmoChrom.

Gold nanoparticle act as ideal nano-objects for storing electric charges, controlling accurately their flow
and design ultra-compact devices for nanoelectronics. However a major challenge is to electrically connect such nanoparticles to electrodes and this is where molecules can play a decisive role. During a PhD thesis completed on Oct. 2018, we have studied a nanoparticle-molecule architecture and highlighted the relationship between the molecular self-organization and the electronic properties. Special advances were made in understanding electric and electrostatic properties of gold nanoparticles induced by molecular functionalization.

The present PhD proposal aims at fabricating more elaborate molecular connections based on molecular switches (diarylethene molecules, abbreviated DAE). DAEs can be switched OFF or ON by illuminating them with UV or visible light, respectively. By synthesizing dimers of gold nanoparticles, connected by DAEs molecules, we will fabricate the elemental building block of an electric switch controlled by light.

The nanoparticles will also serve as plasmonic antenna for increasing the switching rate. These nanoparticle dimers will be assembled by a tailored chemistry, which is presently under testing (see figure).

The PhD work will largely consist on experimental work based on atomic force microscopy (AFM), and more specifically of a new mode of conducting AFM. Gaining a deep understanding of the electronic
processes at the nanoscale is also one aim of this PhD work. These experiments will be coupled to a new hypermicroscopy technique for monitoring the optical spectra of the nanoparticle dimers. Several national and international collaborations have been started on this topic: with chemist (synthesis of DAE molecules), with theoreticians (DFT calculations for clarifying the molecular organization) and physicists (conductance measurement of single DAE molecules). The PhD student will be encouraged to take an active part in these collaborations.

Former work on these topic:
[1] Zhang, Y.; Pluchery, O.; Caillard, L.; Lamic-Humblot, A.-F.; Casale, S.; Chabal, Y. J.; Salmeron, M.,
Sensing the Charge State of Single Gold Nanoparticles via Work Function Measurements. Nano Letters
2015, 15, (1), 51-55.
[2] Pluchery, O.; Caillard, L.; Dollfus, P.; Chabal, Y. J., Gold nanoparticles on functionalized silicon
substrate under Coulomb blockade regime: an experimental and theoretical investigation. J. Phys. Chem.
B 2018, 122, (2), 897-903.
[3] Bossard-Giannesini, L.; Cruguel, H.; Lacaze, E.; Pluchery, O., Plasmonic properties of gold
nanoparticles on silicon substrates: Understanding Fano-like spectra observed in reflection. Applied
Physics Letters 2016, 109, (11), 111901.
[4] Snegir, S.; Khodko, A. A.; Sysoiev, D.; Lacaze, E.; Pluchery, O.; Huhn, T., Optical Properties of Gold
Nanoparticles Decorated with Furan-based Diarylethene Photochromic Molecules J. Photochem.
Photobiol. A 2017, 324, 78-84.

Techniques involved: Atomic Force Microscopy, Kelvin Probe Force Microscopy, UV-visible
spectroscopy, nanoparticle deposition, chemical functionalization.

Sources of funding available: PhD funded by the ANR (Agence Nationale de la Recherche, France), with a monthly salary of 2135 €/month.

Application : send a CV with a motivation letter before 20 June 2019 to olivier.pluchery@insp.jussieu.fr