Antonio Agresti received his master degree in Electronic Engineer (with honors) from the University of Rome Tor Vergata (Italy) in 2011 and his Ph.D. degree with distinction and European label at the same University in 2015 with a period of six month spent at IMEC (Leuven, Belgium). He got a post-doctoral research fellow till 2016 from C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy) at the University of Rome Tor Vergata (Italy), in the international context of graphene flagship. He is currently a researcher at the Department of Electronic Engineering at the University of Rome Tor Vergata. Currently, his research activity mainly concerns the realization, optimization and spectral characterization of organic and hybrid photovoltaic devices and in particular Dye Sensitized Solar Cells (DSSCs), small molecule based solar cells and perovskite based devices. Moreover, he is involved in the development of perovskite-graphene based photovoltaic technology by focusing the attention on the scaling-up towards large modules and panels. In the context of graphene flagship, he gained experience in graphene-based and 2-dimensional materials, perovskite-graphene interface optimization related to device’s efficiency and stability. At the same time concerning the device’s long-term stability, his skills include Raman and fluorescence spectroscopy characterizations. He has been co-authoring more than 20 papers, besides a number of other publications (1 book chapters, several conference proceedings, etc.) and several invited talks.
Title and Abstract of the Speech:
The Future of Perovskite Solar Cells between Stability and Scaling-Up: The Role of 2D Materials
Antonio Agresti1, Sara Pescetelli1, Francesco Bonaccorso2, Aldo Di Carlo1
1C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Electrical Engineering Department, University of Rome Tor Vergata, Via del Politecnico 1, I-00133 Rome, Italy
2Graphene Labs, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy
Recently, the rise-up of perovskite solar cell (PSC) technology has been testified by the rapid increase of power conversion efficiency (PCE) overcoming 23% on small area device. However, the scientific community is now facing up with stability and scalability issues that still prevent the final assessment of perovskite photovoltaics into the market.
Indeed, the PSC life time is strongly affected by the operative conditions such as humidity, operating temperature and prolonged light soaking that activate irreversible degradation mechanisms in the bulk of organic/hybrid layers and at the device interfaces. Among them, metal atom diffusion from the counter-electrode toward the perovskite active layer is known to be thermally activated while light soaking induces phase segregation at perovskite/charge transport layer (CTL) interfaces by penalizing the charge injection/extraction at the electrodes and eventually the device PCE stability over time. Moreover, very few works reported about a feasible way to scale-up perovskite technology from lab-scale devices to large area modules, since the PCE falls suddenly down as soon as the active area dimension increases. This is mainly due to i) the increasing of contact series resistance (from the glass/FTO side), ii) the difficulty in controlling perovskite morphology and uniformity on large area substrates, iii) the role of interfacial charge recombination that became prominent as soon as the interfacial surface area increase.
In this work we demonstrate the possibility to integrate graphene and bi-dimensional (2D) materials within the device architecture by demonstrating an i) improved perovskite crystallization on large area substrates,  ii) improved charge transfer efficiency  and stability of perovskite/CTLs [4,5] by significantly enlarging the device lifetime, and iii) an easy scalability on large area module due to the possibility to produce large amount of 2D materials by liquid phase exfoliation technique.
Impressive results have been carried out on large module by integrating graphene and functionalized MoS2 into the device architecture and by overcoming the series resistance problem by optimizing the module layout with laser-assisted patterning processes.  Notably, large area module with the following structure glass/FTO/graphene-doped compact TiO2 (G-cTiO2)/graphene-doped mTiO2 (G-mTiO2)/perovskite/spiro-OMeTAD/fMoS2/gold showed 13.4% on an active area of 108 cm2, nowadays representing the state of art for perovskite photovoltaics. Together with the demonstrated stability improvement of GRMs-based perovskite solar cell  the demonstrated scalability of perovskite solar technology paves the way for a feasible and not far away commercialization of perovskite photovoltaic technology.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 785219 – GrapheneCore2.
- S. Yang, B.-W. Park, E. H. Jun, N. J. Jeon, Y. C. Kim, D. U. Lee, S. S. Shin, J. Seo, E. K. Kim, J. H. Noh, S. Seok,” Iodide management in formamidinium-lead-halide–based perovskite layers for efficien solar cells”, Science 356, 1376–1379 (2017).
- Agresti, S. Pescetelli, A. L. Palma, A. E. Del, R. Castillo, D. Konios, G. Kakavelakis, S. Razza, L. Cinà, E. Kymakis, F. Bonaccorso, and A. Di Carlo, “Graphene Interface Engineering for Perovskite Solar Modules: 12.6% Power Conversion Efficiency over 50 cm2 Active Area”, ACS Energy Lett. 2, 279 (2017).
- Biccari, F. Gabelloni, E. Burzi, M. Gurioli, S. Pescetelli, A. Agresti, A. E. Del Rio Castillo, A. Ansaldo, E. Kymakis, F. Bonaccorso, A. Di Carlo, A. Vinattieri, Adv. Energy Mater. 1701349 (2017).
- Busby, A. Agresti, S. Pescetelli, A. Di Carlo, C. Noel, J.-J. Pireaux, L. Houssiau, Aging Effects in Interface-Engineered Perovskite Solar Cells with 2D Nanomaterials: a Depth Profile Analysis, Materials Today:Energy, just accepted (2018).
- Agresti, S. Pescetelli, B. Taheri, A. E. Del Rio Castillo, L. Cinà, F. Bonaccorso, and A. Di Carlo, Graphene–Perovskite Solar Cells Exceed 18% Efficiency: A Stability Study”, ChemSusChem 9, 2609 (2016).
- Agresti, A.; Pescetelli, S.; Najafi, L.; Castillo, A. E. D. R.; Busby, Y.; Carlo, A. Di. Carlo, “Graphene and Related 2D Materials for High Efficient and Stable Perovskite Solar Cells”, IEEE Internaional Conference on nanotechnology; IEEE Xplore (2017).