PhD position in Ultrafast spectroscopy of bio-mimetic photo-switches (M/F)

Job Description

Thesis Subject

Thesis in Physics: "Ultrafast spectroscopy of photoisomerization of biomimetic photoswitches";
Topics: Molecular physics, laser spectroscopy, femtosecond lasers, nonlinear optics

The topic of the thesis is part of the French-German project Femto-Switch, which proposes an interdisciplinary approach between physicists and chemists to study ultrafast molecular photoswitches. The main question is how to control the efficiency of photoisomerization in organic molecules by chemical design? We are inspired by biological photoswitches such as retinal which are known for their isomerization rates on the scale of 0.2 to 5 ps. In the framework of this thesis, several molecules of different families will be studied by classical ultrafast spectroscopy and by photo-emission spectroscopy (TRPES) which is very promising to highlight the energy landscape which conditions the speed and efficiency of photo-isomerization.
Within Femto-Switch, we are five partners, chemists and physicists, combining organic chemistry, high-level quantum chemistry and advanced ultrafast spectroscopy to answer THE central question: Is there a rational link between the chemical composition and the photoisomerization efficiency of biomimetic photoswitches.

In the present PhD project, the objective is to explore a variety of chemical modifications of biomimetic photo-switches designed by the two chemistry partners. The PhD student will
1) Perform ultrafast spectroscopy (absorption and fluorescence) for systematic studies of ultrafast photoisomerization dynamics and quantum yields (QY) for oxindole and oxopyrrole switches, provided by the chemistry partners.
2) Investigate the effect of excitation wavelength (320–420 nm) and solvent on QY reaction dynamics.
3) Conduct time-resolved photoelectron spectroscopy (TRPES) studies of selected biomimetic photoswitches (with the network partner at MBI Berlin).

Expected results:
1) TRPES and femtosecond UV-vis spectroscopy of switches based on oxindole and oxopyrrole structures
2) A detailed comparison of the excited state dynamics of these switches as a function of chemical composition and solvent.
3) Close interaction with the theory partners modeling these dynamics
4) TRPES: Provide first evidence and potential energies of low emissive, short-lived “phantom” states.

The candidates must hold a master degree in Physics or Physical Chemistry. A good background in molecular spectroscopy and nonlinear optics is a plus, but not mandatory. Additional qualifications such as proficiency in Python and/or Matlab are valuable assets.
The doctoral student will need to work closely with staff from the laboratories associated with the projects. She or he will need to be able to communicate effectively, listen to needs, and share their results regularly through oral and written reports.

Your Work Environment

Most of the experimental studies will be performed at the Institute of Physics and Materials of Materials Strasbourg (IPCMS), in the BIODYN (“Biophysics and Dynamics of Organic Nanostructures”) team . It is led by J. Léonard and S. Haacke (https://www.ipcms.fr/en/equipe/biodyn/).

IPCMS is an interdisciplinary physics and chemistry laboratory with a total staff of 230. Located on the Cronenbourg campus, it is easily accessible by public transport and bicycle, 20 minutes from Strasbourg's historic city center. On-site catering is available, with subsidized meals for PhD students.

Femtosecond TRPES in the liquid phase will be carried out at the Max-Born Institute Berlin (https://mbi-berlin.de/homepage), during three or four one-month visits throughout the duration of the PhD. Travel and accommodation expenses will be covered.
The project's partner teams meet monthly for online meetings, allowing them to share the latest results and plan the next steps.

The position should ideally be filled by October 1st, 2026.

Constraints and risks

Laser safety
Minor chemical hazards (solvent handling)

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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