Abstract Details


Katarzyna Posmyk

PhD student at Wroclaw University of Science and Technology

Katarzyna Posmyk

PhD student at Wroclaw University of Science and Technology

Abstract Name:

Excitons in two-dimensional metal-halide perovskites

Symposium:

Symposium B: Materials Discovery, Modification & Functionalisation

Topic:

B6: Perovskite & Organic Materials

Talk

• Excitons in two-dimensional metal-halide perovskites

Abstract Contributing Authors:

Katarzyna Posmyk 1,2, Natalia Zawadzka 3, Łucja Kipczak 3, Mateusz Dyksik 1, Alessandro Surrente 1, Duncan K. Maude 2, Tomasz Kazimierczuk 3, Adam Babiński 3, Maciej R. Molas 3, Wakul Bumrungsan 4, Chanisara Chooseng 4, Watcharaphol Paritmongkol 4,5, Mirosław Mączka 6, William A. Tisdale 5, Paulina Płochocka 2, 1, and Michał Baranowski 1 1 Wrocław University of Science and Technology, Wrocław, Poland 2 Laboratoire National des Champs Magnetiques Intenses, CNRS-UPS-INSA-UGA, Toulouse, France 3 University of Warsaw, Warsaw, Poland 4 Vidyasirimedhi Institute of Science and Technology, Rayong, Thailand 5 Massachusetts Institute of Technology, Cambridge, Massachusetts, United States 6 Institute of Low Temperature and Structure Research, Wrocław, Poland

Abstract Body:

Two-dimensional (2D) lead halide perovskites are a group of hybrid organic-inorganic semiconducting materials, considered an alternative for applications in photovoltaics and optoelectronics. Their structure can be seen as the “natural” quantum wells, where slabs of metal-halide octahedral units are surrounded from both sides by large organic cations, acting as potential barriers. Owing to the possible adjustment of the structure and chemical composition of the crystals, optical properties of 2D perovskites can be tuned over a range unattainable for their three-dimensional counterparts. This makes them not only intriguing in terms of their application potential, but also a very attractive object of fundamental studies, in particular, the investigation of exciton physics.

As a consequence of both the quantum and dielectric confinement, the exciton binding energy can reach several hundreds of millielectronvolts, greatly enhancing all excitonic effects in this system.  Induced significant spacing of states in the exciton fine structure and whether or not the lowest excitonic state interacts with photons are also crucial aspects affecting the performance of a device based on 2D perovskites. Gaining a deeper understanding of the exciton fine structure is therefore very important from the point of view of potential applications. 

We  combine the optical spectroscopy techniques with the use of magnetic field to investigate the excitonic properties of perovskite compounds with the general formula (PEA)2(MA)n-1PbnI3n+1, where n=1,2,3,4 denotes the number of octahedra layers within a slab. We investigate in detail the exciton fine structure [1,2], as well as the evolution of the optoelectronic properties of 2D perovskites with the change of the confinement strength [3]. Our results provide a further insight into one of the “tuning knobs” of this material system, which is gradual progression of the properties from the 2D limit to bulk. This forms the solid base for further studies of the band structure and excitons in lead halide perovskites.

[1]         K. Posmyk et al., Journal of Physical Chemistry Letters 13, 4463-4469 (2022)
[2]         K. Posmyk et al., Advanced Optical Materials,  2300877 (2023)
[3]         K. Posmyk et al., Journal of the American Chemical Society, 146, 7, 4687–4694 (2024).

Attached Figure:

Figure1.png

Submission Type:

Talk

Our Partners

The exciting conference programme is co-convened with the following partners:

Our Sponsors

ICANS30 is proudly sponsored by: