Interfaces management of HYbrid PERovskite based SOlar cells – HYPERSOL

In this project, two main approaches will be investigated:
1. The first approach is inspired by the field of silicon solar cells and consists in using doping
to design degenerate semiconducting contacts, thereby avoiding surface recombination at
metal contacts,
2. The second is instead inspired by the field of organic electronics and consists in tuning
the metal work function by introducing Self Assembled Monolayers (SAM) between the electrode and the HOIP. In addition, this approach can be an alternative to n type doping, which is more challenging than p type doping in HOIP.

The main highlights were:
• The discovery of the interaction of fluorinated molecules on the surface of hybrid halogenated perovskites. This interaction had never been mentioned before and we took advantage of it to modify the output work of the perovskites and protect them from humidity.
• The combination of deuterated methylammonium and PM-IRRAS to monitor and model the effect of water on the perovskite layer.

The work to come will focus on bulk doping to define the optimal manufacturing parameters. Finally, both doping and control of interfaces will be applied to solar cells.

1. Unexpected surface interactions between fluorocarbons and hybrid organic inorganic perovskites evidenced by PM-IRRAS and their application towards tuning the surface potential, Subha Sadhu, Kyler Aqueche, Thierry Buffeteau, Jean-Marc Vincent, Lionel Hirsch and Dario M. Bassani, Mater. Horiz., 2019, 6, 192
2. Observing the Migration of Hydrogen Species in Hybrid Perovskite Materials through D/H Isotope Exchange, Subha Sadhu, Thierry Buffeteau, Simon Sandrez, Lionel Hirsch, and Dario M. Bassani, J. Am. Chem. Soc. 2020, 142, 10431-10437

Despite the tremendous interest of the scientific community on photovoltaic solar cells based on hybrid perovskites, many physical phenomena are still not fully understood and subject of controversy, such as the role of electrode/perovskite contact quality. The HYPERSOL project intends to introduce new solutions to improve the interface quality of hybrid perovskites solar cells in order to pin the quasi Fermi levels at Ec and Ev so as to extend the open circuit voltage at the thermodynamic limit for a single junction. Because the Voc in such devices is currently between 1 and 1.1V, we can expect an increase of about 30% in the PCE compared to current devices. To this aim, new dopants and customized self-assembled monolayers will be synthesized and introduced into state-of-the-art devices. Advanced characterization techniques will be used to construct a physical model allowing a complete description of the physics of hybrid perovskites solar cells and their optimization.