Public Thesis Defense of Romain SCAFFIDI - ICTEAM
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Next-generation kesterite thin-film solar cells : development, characterization and modeling by Romain SCAFFIDI -
Monday, 8 September 2025 at 2:30 p.m. - Refugiehuis RH-1.16 - Maastrichterstraat 100 - 3500 Hasselt
Kesterite quaternary materials with standard composition Cu2ZnSn(S,Se)4 (CZTSSe) and the related alloys provide a promising low-cost and environmentally benign alternative to standard inorganic thin-film photovoltaic technologies. Still, when used as absorbers in solar cells, their efficiency has been stagnating around 12% for the past decade, which remains insufficient to reach commercialization. To cope with this, their dominant performance barriers must be overcome, and specific attention should focus on solving their large open-circuit voltage deficit.
First, standard physical deposition processes must evolve towards molecular ink chemical routes to allow better morphology and control of the phase formation while enabling flexible alloying of other elements to counteract disorder and intrinsic point defects. This work tackles this challenge for the specific case of Ge alloying and demonstrates its ability to provide bandgap tunability without compromising material quality and device performance potential. Second, this migration of the kesterite deposition baselines towards solution processes induces the need for an update of the characterization and modeling state-of-the-art accounting for their enhanced opto-electronic properties. Such a study is realized through the in-depth analysis of temperature-dependent current-voltage measurements in combination with SCAPS simulations.
Strong evidence of a closer-to-ideal device behaviour is obtained, and robust hypotheses are drawn concerning the dominant recombination and shunt mechanisms. Overall, this work encompasses both the development of enhanced kesterite solar cells and their advanced opto-electrical characterization and modeling, very relevant to the next-generation of thin-film photovoltaic technologies.
Jury members
- Prof. Denis Flandre (UCLouvain) (Supervisor)
- Prof. Bart Vermang (UHasselt) (Supervisor)
- Prof. Ronald Thoelen (UHasselt) (Chairperson)
- Prof. Laurent Francis (UCLouvain) (Secretary)
- Prof. Guy Brammertz (UHasselt)
- Prof. Patrizio Manganiello (UHasselt)
- Prof. Xiaojing Hao (UNSW)
- Prof. Johan Lauwaert (UGent)
- Dr. Ivan Caño Prades (UPC)