Starting: from 02/2025 (flexible)

Duration: 6 months

Laboratory: Center for Nanosciences and Nanotechnologies (C2N)

Address: 10 Boulevard Thomas Gobert, 91120 Palaiseau, France

Supervisor(s): Amaury Delamarre, Stéphane Collin

Phone number: 01 70 27 04 80

Send application to: amaury.delamarre@cnrs.fr, stephane.collin@cnrs.fr

The Institute:

The Centre for Nanosciences and Nanotechnology (C2N) is a joint research unit between the CNRS and Université Paris-Saclay. The center develops research in the fields of material science, nanophotonics, nanoelectronics, and nanotechnologies, covering all the range from fundamental to applied sciences. The PhD thesis offered here will take place in the Sunlit Team, which develops innovative approaches for solar cells, aiming at high efficiencies, cost reduction and reliability of the photovoltaic devices.

Scientific project:

Photovoltaic is playing a major role in the energy transition, and its share in electricity generation is expected to keep rising to contribute to the net zero emission goals by 2050. 90 % of the currently produced solar panels are using silicon solar cells with gradually decreasing costs and increasing efficiency. Nevertheless, this efficiency is nearing its physical limit of 29.4 %, with

27.3 % obtained in laboratory. In order to overcome this limit, the next generation of solar cells will consist in tandem devices, combining two materials of different bandgaps. In the Sunlit team in particular, III-V on silicon and CIGS on silicon devices are being produced.

Those new devices present exciting challenges: new fabrication steps, new materials and combinations of materials, new aging mechanisms and failure modes… All those aspects call for a better understanding of their working principles, through new characterization methods, data analysis and tests under various environments. We propose in this internship to take advantage of the recognized know-how of the C2N and its partners, in terms of luminescence characterization and state-of-the-art equipment, to tackle this challenge.

The main objective of the project is to develop a new technique based on simultaneous electrical and optical carrier injection in solar cells, with which we showed that we can access the current collection efficiency in each subcells, with a spatial resolution. Such a set of data cannot be obtained otherwise, allowing us to achieve a unique in-depth understanding of the tandem cell working mechanisms.

This internship comprises an extensive part of experimental work in the laboratory as well as data treatment. We expect the intern to propose further developments of the techniques already existing at the laboratory, as well as to suggest the exploration of new methods. He / she will propose models to explain the observed phenomena, and design experiments for their validation, using his / her own knowledge as well as the scientific literature. The intern will take advantage of the unique luminescence characterization method available at the C2N and partners, as well as complementary methods (solar simulator, quantum efficiency). This environment will provide various opportunities to tackle this project challenge and gain experience.

Profile:

The candidate must possess solid knowledges in material physics and characterization.

He / she must show good project management skills, for the development of measurement procedures involving numerous parameters. He / she will be able to work independently and suggest innovative solutions to reach the project objectives. Collaborative work being at the core of the program, communication skills are required for team working as well as regular presentation of work progress in internal meetings.

This internship can be followed by a PhD.

Websites: https://sunlit-team.eu