Science Faculty

PhD proposition. Upconverting Core/shell nanoparticles as light harvesting material for photocatalysis

Some teams, including ours, have tried this approach in the past few years and have indeed demonstrated that combining an upconverting material with titania leads to IR photocatalysis. However since the process is highly non-linear (up to the 5th order) the results were obtained under laser excitation and such a conversion has not been detected under a standard solar irradiation. Our project UPHocat aims at bypassing this non-linear bottleneck by modifying 2 key aspects of the process:

- combining the absorption of different wavelengths to significantly decrease the order of non linearity of the UC process and making it compatible with the excitation density of the sun.
- replace the radiative energy transfer to TiO2 via an emission and absorption of UV photons by a more efficient process of non-radiative energy transfer (ET).
This project has been recently selected by the French research agency (ANR) and a PhD position is available in this frame.

The PhD student will have the possibility to work on three aspects of this project:

- Develop an experimental setup dedicated to the measure of transfer rates between different electronic system over a wide range of wavelength and times.
- Improve a simulation tool able to predict the energy migration between materials in a core (multiple) shell structure. The spectroscopic parameters of the model will be defined on the basis of the spectroscopic measurement (previous item).
- Develop chemical synthetic strategies to develop those systems.
The project combines theoretical predictions, synthesis and performance analysis. It is thus interdisciplinary in nature and will be performed in close collaboration with the two teams at ILM and IRCELYON.

The PhD thesis is due to start between October 2017 and February 2018.

Contact : gilles.ledoux@univ-lyon1.fr (04-72-44-83-38) / shashank.mishra@ircelyon.univ-lyon1.fr (04-72-44-53-22)