The work has been structured in 5 interconnected work packages (WPs): 4 scientific WPs, each one connected to a specific project’s objective, and an extra work package dedicated to dissemination and exploitation activities. The first work package focused on developing photochemically stable halide perovskite materials with both wide and narrow bandgaps. Narrow bandgap materials have been achieved by using Sn-based, fully iodide halide perovskite compositions, which are notoriously electronically p-doped semiconductors. We performed an in-depth study of their optoelectronic properties, highlighting the interplay between defects contributing to doping and the ones which instead act as non-radiative recombination channels. These results have been mainly included in 2 publications: Mater. Horiz., 2022,9, 1763-1773 and Adv. Sci. 2022, 2202795. Wide bandgap materials have been achieved through mixed halide I/Br Sn-based perovskite compositions. We showed for the first time that this class of materials do not suffer from photo-induced halide segregation and that a fine tuning of Br content can lead to films with reduced doping and improved optoelectronic quality. These results have been published in the following articles: ACS Energy Lett. 2023, 8, 6, 2801–2808 and ACS Energy Lett. 2023, 8, 9, 3876–3882.
The second work package focused on engineering fully printable carbon-based architectures for the fabrication of printable solar cells. Together with VTT in Oulu, Finland, which took part in the project BOLLA as Secondment organization, we were able to study the rheological properties of both commercial and home-made conductive pastes to optimize the printing quality and engineer solar cell devices consisting of a triple-mesoscopic stack where the perovskite active material gets infiltrated. The third work package looked at the characterization of the electrochemical system for the electrical oxidation of dyes in water, which are common organic pollutants. We used treated carbon paper sheets as electrodes and we optimized the voltage response of the system at different applied voltages, finding a maximum degradation rate at 1.4 V. Finally, in the last experimental work package, we designed photovoltaic devices to be coupled with the electrochemical system to perform photo driven oxidation of organic pollutants in water. We obtained 90% removal of organic dyes by using two carbon-based cells connected in series, with maximum power point voltage and current of 1.2 V and 19.5 mA, respectively.
BOLLA's results have been disseminated through conference presentations, journal publications and outreach activities. The Fellow presented her research at five different conferences throughout the duration of the Action where she contributed with 4 talks and 1 poster and 4 articles have been already published in peer-reviewed journals. Additional manuscripts that use data collected during this fellowship are currently under development. During the project she also organized a Conference Science Cafè as part of the Genoa Science Festival 2022.
