Function:                 Intern H/F

Contract:                 Internship agreement

Starting date:         As of February 3rd 2025 (to be defined)

Duration:                 6 months

Workplace:             IPVF – 18 bd Thomas Gobert, 91120 Palaiseau (France)

Education:              Master 2 in Chemistry / Material Science

Ref.:                          PR-F-L-11-ST

IPVF – Institut Photovoltaïque d’Île-de-France

IPVF is a scientific and technical pole dedicated to the research and development of solar technologies. It permanently hosts its own staff, as well as the employees of its partners and external companies. IPVF aims to become one of the world’s leading centers for research, innovation, and training in the field of energy transition.
IPVF primary objective is to improve the performance and competitiveness of photovoltaic cells and develop breakthrough technologies by relying on four levers:

• Ambitious research program.
• The hosting of more than 200 researchers and their laboratories on its Paris-Saclay site.
• A state-of-the-art technology platform (8,000 m²) open to the photovoltaic industry actors, with more than 100 state-of-the-art equipment units located in clean rooms.
• A training program mainly based on a master’s degree, the supervision of PhD students, and continuing education.

Brief history:

The IPVF was founded in 2013 on the initiative of the French government, EDF, TotalEnergies, Air Liquide, CNRS, Ecole Polytechnique, Horiba and Riber. Bringing together more than 150 researchers, our 8,000 square meter Paris-Saclay platform is a unique platform for all types of deeptech research and innovation.

The IPVF aims to remain:
• A world leader in photovoltaic-related R&D. By federating the best French teams in the field of research, innovation and industrial production, in partnership with major international institutes, particularly in Europe,
• A leader in the development of photovoltaic technology bricks in line with market trends,
• A reference in sending the most promising R&D concepts to the industry.

INTERNSHIP CONTEXT

While silicon (Si) photovoltaics has almost reached its maximum theoretical efficiency, perovskite solar cells (PSC) have emerged in the last decade as a new generation of photovoltaics, with a record efficiency of 26.1%, almost matching that of Si cells. To reach high efficiency and long-term stability, perovskite solar cells need to be passivated.

In the last few years, ammonium salts have emerged as the most promising passivation strategy and are used in all record efficiency perovskite devices¹. They have the particularity to generate a 3D/quasi-2D interface when deposited on top of perovskite. To date, they are introduced by spin coating upon dissolution in isopropanol (IPA), with proof of concept of deposition by slot-die coating², which is key for the upscaling this strategy.

At IPVF we have been concentrating on i) identifying the most promising ammonium salts to create a quasi-2D layer ii) optimizing layer properties thanks to additives iii) transferring knowledge gained on spin-coated perovskite to slot-die deposited perovskite. It is now important to i) start upscaling this technology ii) improve control over the layer properties.

The conversion of evaporated PbI2 on top of perovskite to quasi-2D perovskite was reported as an efficient strategy to enable for conformal coverage of the quasi-2D layer and controlled thickness³. By converting such layer using slot-die coating we would control the 2D layer properties with an upscale process. The aim of the internship will be to explore this strategy at IPVF for the first time.

1. Teale, ; Degani, M.; Chen, B.; Sargent, E. H.; Grancini, G. Molecular Cation and Low-Dimensional Perovskite Surface Passivation in Perovskite Solar Cells. Nat Energy 2024, 9 (7), 779–792. https://doi.org/10.1038/s41560-024-01529-3.

2. Teixeira, C.; Fuentes-Pineda, R.; Andrade, L.; Mendes, A.; Forgács, D. Fabrication of Low-Cost and Flexible Perovskite Solar Cells by Slot-Die Coating for Indoor Mater. Adv. 2023, 4 (17), 3863–3873. https://doi.org/10.1039/D3MA00285C.

3. Azmi, R.; Utomo, D. S.; Vishal, B.; Zhumagali, S.; Dally, P.; Risqi, A. M.; Prasetio, A.; Ugur, E.; Cao, F.; Imran, I. F.; Said, A. A.; Pininti, A. R.; Subbiah, A. S.; Aydin, E.; Xiao, C.; Seok, S. I.; De Wolf, S. Double-Side 2D/3D Heterojunctions for Inverted Perovskite Solar Cells. Nature 2024, 628 (8006), 93–98. https://doi.org/10.1038/s41586-024-07189-3.