Open lecture as part of a mentoring visit by Prof. Claudio Quarti, Mons University (Belgium)

14 05 2025

Please join us for an upcoming open lecture “2D halide perovskites: a theoretical insight on an intriguing class of chemically tunable, dimensionally confined semiconductors”, prepared within the framework of the mentoring visit of Action I.1.1/IV.1.1 “Mentoring Programme”.

At the invitation of the Chemical and Biological Systems Simulation Lab of the Centre of New Technologies (CeNT UW) of the University of Warsaw, the lecture will be given by Prof. Claudio Quarti, from Mons University (Belgium).

The open lecture will take place on Thursday, the 21th of May, 2025, at 15:15-16:15 in room 1.40, located on the first floor of the Faculty of Physics building at ul. Pasteura 5.

Two-dimensional halide perovskites (2DHP) are a very intriguing class of dimensionally confined semiconductors, with interesting prospects for energy-related applications, most notably, photovoltaics and light emission.[1-2] Processed from solution-techniques, these 2D materials are obtained via incorporation of bulky organic compounds, most commonly alkyl- or small aryl- molecules, which act as spacers, intercalating between atomically thin, semiconducting, metal-halide inorganic sheets.[3] The corresponding spatial confinement of the photogenerated species imparts these materials with several novel functionalities, compared to their 3D counterparts, including excitonic emission, dielectric tuning and non-linear properties.[4] In addition, several studies are demonstrating the possibility of incorporating more and more complex spacers, like p-conjugated compounds, further widening the possibilities of tuning their electronic and optical properties.[5]

In this talk, we will try to provide a broad overview of the electronic and optical properties of this intriguing class of 2D-compounds, in light of their dimensional and compositional flexibility. Starting with the most common 2DHP incorporating electronically inert short alkyl chains, we will show the impact of spin orbit coupling on the electronic band structure,[6] and we will then discuss the vibronic signatures that point out towards the formation of polarons in these materials.[7] In the effort of bridging long time-established spectroscopic studies[4] with modern ab-initio simulation techniques, we will then discuss the excitonic properties of these materials, by combining symmetry analysis with ab-initio solution of the Bethe-Salpeter Equation.[8] Finally, we will explore the chemical space of these materials, by considering the impact of the substitution of divalent metal species (Sn²⁺, Pb²⁺) with combination of monovalent/trivalent metals (Ag¹⁺, Bi³⁺),[9] as well as the incorporation of p‑conjugated moieties, as spacers.[10]

[1] S. Sidhik, et al., Science, 377, 1425−1430 (2022).
[2] C. Sun, et al., Nat. Commun. 12, 2207 (2021).
[3] B. Saparov and D. Mitzi, Chem. Rev. 116, 4558 (2016).
[4] C. Katan, N. Mercier and J. Even, Chem. Rev. 119, 3140 (2019).
[5] Y. Gao, et al., Nat. Chem., 11, 1151, (2019).
[6] C. Quarti, N. Marchal and D. Beljonne, J. Phys. Chem. Lett., 9, 3416 (2018).
[7] F. Thouin, et al., Nature materials 18, 349 (2019).
[8] C. Quarti, et al., Adv. Opt. Mater., 12, 2202801 (2024).
[9] M. Pantaler, et al., JACS Au 2022, 2, 136 (2021).
[10] F. Ledée, et al., Mater. Horiz., 2021, 8, 1547-1560 (2021).

Claudio Quarti is a FNRS Research Associate at the University of Mons, Belgium. His research focuses on the use of atomistic simulations to study the electronic and optical properties of hybrid, semiconductors for energy- and information-related applications. Most notably, he has been widely active in the field of halide perovskite materials.

He earned his PhD in Materials Engineering at the Polytechnic University of Milan in 2013. After a post-doctoral fellowship at the CNR (the Italian National Research Council), he moved to the university of Mons, where he opened the research line dedicated to halide perovskite materials and hybrid/inorganic semiconductors. In a context of a personal FNRS grant, he had the opportunity to work 18 months as CNRS post-doctoral fellow, under the direction of Dr. Claudine Katan and Prof. Jacky Even, who pioneered the theoretical research on halide perovskites.

In 2021, he successfully obtained a permanent position as Research Associate of the FNRS and in 2024 he earned a FNRS incentive grant, to build his research unit. Over the years, he build an extended network of collaborations, involving research groups in France, Italy, Switzerland, Luxemburg, Poland, and United States. He is also member of the directing committee of the CECI consortium, which manages the computational facilities in the region Wallonia.