Job offer

European Commission; France; Sur place; EUR 40 000 - 60 000; Plein temps

Résumé du poste

Une opportunité passionnante se présente pour un doctorant en physique au sein d'un projet de recherche sur le couplage fort dans des cavités optiques. Le candidat sera responsable de la fabrication de dispositifs électroniques organiques et contribuera à des caractères optiques importants. Ce poste offre un environnement de travail stimulant et une chance d'explorer des concepts novateurs en optoélectronique, avec un fort potentiel d'impact dans le domaine.

Qualifications

• Formation en Physique ou Sciences des Matériaux.
• Motivé et intéressé par la fabrication de dispositifs électroniques organiques.

Responsabilités

• Fabriquer des dispositifs organiques en laboratoire.
• Réaliser des caractérisations optiques et des simulations numériques occasionnelles.

Connaissances

Motivation pour le travail interdisciplinaire

Expérience pratique en dispositifs organiques

Formation

Physique, Sciences des Matériaux ou Électronique

Description du poste

Organisation/Company CNRS and Université de Bordeaux Department Science de la Matière et du Rayonnement Research Field Physics » Optics Physics » Applied physics Physics » Electronics Researcher Profile First Stage Researcher (R1) Positions PhD Positions Country France Application Deadline 30 Jun 2025 - 10:00 (Europe/Paris) Type of Contract Temporary Job Status Full-time Is the job funded through the EU Research Framework Programme? Other EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Strong coupling in an optical cavity [1] is a phenomenon that has been studied since the 1990s.It occurs when molecules (or atoms) are in resonance with an optical cavity mode (e.g., Fabry–Pérot). In the strong coupling regime, the molecules and the electromagnetic field form hybrid collective excitations known as polaritons. In this regime, one can observe Vacuum Rabi Splitting , which is manifested, for instance, by the splitting of the absorption peak of the isolated molecule (as the system transitions from the weak coupling regime to the strong coupling regime). These two peaks are associated with the existence of two polaritonic states (Lower and Upper Polaritons, LP and UP) that form around the Singlet state (S1), separated by an energy gap (VRS) that reflects the strength of the light–matter coupling [2].

One consequence is that the electronic levels of the molecules involved are shifted due to the presence of the cavity. This allows for the engineering of "artificial" materials, with, for example, a lowered Singlet state energy level. This promotes energy transfer from non-radiative Triplet states (T1) to Singlet states (S1), which can then emit via fluorescence. This phenomenon is called RISC: Reverse InterSystem Crossing. In the strong coupling regime, this optically induced RISC phenomenon (unlike in TADF materials) has already been both theoretically predicted and experimentally observed [3], which is highly promising. It could significantly enhance the internal quantum efficiency of OLEDs. In organic solar cells, recent studies [4] have shown that strong coupling can both broaden the absorption spectrum and increase the internal quantum efficiency by extending the exciton lifetime. This area of research could open a new technological pathway toward the development of novel optoelectronic components based on an innovative physical effect.

Moreover, the strong coupling regime also opens up new perspectives for studying charge transport in organic semiconductor materials (the field of Polaritronics ). In recent years, the scientific community has observed remarkable phenomena, such as a significantmodification of electronic transport properties—particularly a dramatic increase in mobility—under polaritonic conditions.

• This research topic was recently supported through an Interdisciplinary and Exploratory Research (RIE) project (SpectroPolO) funded by the University of Bordeaux (2024), coordinated by Sophie Fasquel in collaboration with Rémi Avriller, a theorist at LOMA. The objective of this project, which began in May 2024, is to fabricate simple optical cavities (multilayer structures of the metal–polymer–metal type) in order to unambiguously characterize the polaritonic regime. The cavity fabrication is carried out at IS, while the optical measurements are conducted at LOMA.
• The recruited PhD student will thus be able to begin their thesis based on the very promising initial results recently obtained, such as the unambiguous characterization of polariton dispersion in a metal/organic polymer/metal optical cavity.

The objective of the PhD thesis is to apply the results obtained in simple optical cavities to organic electronic devices (such as solar cells and OLEDs), which have slightly more complex architectures, and to measure the effect of polaritons on optoelectronic performance (e.g., improvements in quantum efficiency). The selected candidate will be responsible for fabricating organic devices in the lab. In parallel, they will carry out optical characterizations (including angle-resolved absorption spectra in steady-state conditions, as well as time-resolved spectroscopy). Occasional numerical simulations may also be required.

• Candidate profile : Physics or Materials Sciences

The ideal candidate should have a background in Physics, Materials Sciences, or Electronics, with a strong motivation for interdisciplinary work and hands-on experience or interest in fabricating organic electronic devices.