Colloquia

Title: The Landscape of Halide Perovskite Semiconductors in Photonics and Optoelectronics

Abstract

Abstract:

Halide perovskites have been in the spotlight of contemporary research for over a decade, establishing themselves as one of the top-performing technologies in photovoltaics. Today, photovoltaics still hold the wheel for the development of halide perovskites, yet numerous research directions have emerged from their intensive study in the past years. Among them, the incorporation of halide perovskites in semiconductor radiation sensing technologies and the demonstration of stable excitons that enable quantum phenomena to be explored under ambient conditions, stand out. The remarkable properties uniting all these diverse applications derive from the unique electronic structure of halide perovskites, yielding exceptional optical and electrical properties. The exploration of this class of materials typically begins with the development of synthetic chemistry protocols which can be informed by changes in their electronic band structure and their optical spectra signatures. This iterative loop between synthesis, electronic structure and optical spectra promises new attractive properties, producing interesting new physics along the way.

In this talk, I will discuss selected topical directions of halide perovskite research, from device engineering to crystal growth, spectroscopy, and exploratory materials design. I will describe how the optoelectronic properties of perovskites can be fine-tuned via small changes in their chemical composition and their crystallographic atom arrangement, thus directed towards specific applications with specific photophysical demands. I will conclude with selected recent examples of promising applications revolving around the strong presence of stable excitons in these materials, and discuss the impact of phonon-assisted optical processes. While we are still far away from fully grasping the underlying physics governing halide perovskites, the discussed approaches broaden the scope of application of these materials and enable new directions towards materials design and discovery.

Acknowledgements: CCS acknowledges the Ministry of Science and Higher Education of the Russian Federation (Megagrant no. 075-15-2022-1112) for financial support.

Short bio

Constantinos (Costas) Stoumpos was born in Athens, Greece in 1983. In 2001 he attended the Chemistry Department at the University of Patras where he obtained both his B.S. (2006) and Ph. D. (2009) degrees, the latter on the coordination chemistry of 3d-metals targeting the discovery of new Single-Molecule Magnets (SMMs) and Molecular Nanomagnets (MNMs). In February 2010 he joined the group of Mercouri G. Kanatzidis at the Department of Chemistry of Northwestern University, IL, USA as a postdoctoral fellow working on the synthesis of p-block halide perovskites for near-IR optical applications. On January 2012 he moved to the Materials Science Division (MSD) of Argonne National Laboratory (ANL), IL, USA, where he worked on the single-crystal growth of dense, wide-bandgap halide and chalcohalide compounds for high energy radiation detection. In 2014 he returned to Northwestern University working on the development of halide perovskites for energy related applications. In 2018 he was appointed at the Department of Materials Science and Technology (currently Materials Science and Engineering) of the University of Crete, as an Associate Professor. Since 2022 he is heading the newly founded “Photonics of Crystals” laboratory at the St. Petersburg State University.