PhD Thesis Conjugated polymer nanoparticules for energy

Context and mission:

Among renewable energies, solar energy, which is infinitely abundant, is particularly interesting. It can be used to produce electricity by means of photovoltaic cells or green hydrogen by the photocatalytic dissociation of water.

The PhD project aims at designing aqueous dispersions of organic semiconductor nanoparticles (NPs) composed of electron donor and acceptor materials. Aqueous dispersions of these NPs allow the environmentally friendly implementation of organic photovoltaic cells by conventional printing processes.1,2 Moreover, it has been recently shown that these same particles could be used for the photocatalytic production of hydrogen by water splitting.3 The properties of these NPs are strongly conditioned by their chemical and structural morphology. Along with laboratory based tools their detailed characterization requires state-of-the-art tools such as those using the synchrotron X-rays available at the Synchrotron SOLEIL in Saint-Aubin (STXM microscopy4 , soft x-ray ptychography5 and GIWAXS). It will allow to establish a correlation between the internal structure of NPs and their efficiency for the targeted applications.

The PhD work will be divided in several phases:

- Synthesis or modification of conjugated polymers,

- Preparation of nanoparticles by mini-emulsion or nanoprecipitation techniques,

- Characterization by STXM, ptychography, photoluminescence, X-ray diffraction,

- Applications of NPs: Aqueous dispersions will be used for the photocatalytic generation of hydrogen under different irradiation conditions. In parallel, the optoelectronic properties of the NPs will also be measured.

Working environment

The PhD student will be hosted in the PolyFuN team of the Institute of Chemistry and Processes for Energy, Environment and Health (ICPEES UMR7515), which has been developing organic semiconducting polymers for organic electronics including OPV for almost 20 years. He will spend most of his time there. He will also stay regularly at SOLEIL (about 2 weeks every 2 months depending on the progress of his work) to characterize his materials and participate in the development of the techniques necessary for his project. SOLEIL has a lodging house to accommodate the users of the beamlines. Finally, he will benefit from the expertise of T. Cottineau and the photocatalytic platform available at ICPEES for hydrogen production applications and from the skills of the STELORG (Strasbourg organic electronics) consortium for photovoltaic applications.