ABSTRACT: We discuss the discovery and recent developments of colloidal lead halide perovskite nanocrystals (LHP NCs, NCs, A=Cs+, FA+, FA=formamidinium; X=Cl, Br, I) [1-5]. LHP NCs exhibit spectrally narrow (<100 meV) fluorescence, originating form bright triplet excitons , and tunable over the entire visible spectral region of 400-800 nm. Cs- and FA-based perovskite NCs are promising for LCD displays, for light-emitting diodes and as precursors/inks for perovskite solar cells. Perovskite NCs also readily form long-range ordered superlattices, which exhibit accelerated coherent emission (superfluorescence) . Unique structure engineerability of perovskites allows for (nearly) independent tuning of the emission color and radiative rates, which can be used in printable unicolor security tags .
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BIOGRAPHY: Maksym Kovalenko is a professor at ETH Zürich (Swiss Federal Institute of Technilogy in Zürich), Switzerland. He received his PhD degree in nanoscience and nanotechnology from Johannes Kepler University Linz, Austria, in 2007. He then joined the University of Chicago as a postdoctoral fellow, studying the surface chemistry and self-assembly of colloidal nanocrystals. In 2011, Kovalenko joined ETH Zürich and Empa (Swiss Federal Laboratories for Materials Science and Technology) as a tenure-track assistant professor, an associate professor in 2017, and a full professor in 2020. His research interests include chemistry, physics, and applications of functional inorganic materials, including colloidal quantum dots, novel solid-state compounds, and materials for electrochemical energy storage. Present research efforts of the Functional Inorganic Materials group concern: (i) the precision synthesis of highly luminescent semiconductor nanocrystals; (ii) nanocrystal surface chemistry; (iii) exploration of novel semiconductor materials by solution- and solid-state synthesis; (iv) novel semiconductors for hard radiation detection; (iv) novel materials and concepts for Li-ion and post-Li-ion rechargeable batteries. Many of these activities are strongly linked to industrial partners. Academic collaborations involve various groups ranging from first-principles theory of materials to applications in photovoltaics and thermoelectrics He has co-authored 270 publications, 3 book chapters, and holds 11 patent applications. He has been the recipient of highly prestigious awards including ERC Consolidator Grant (2018), ERC Starting Grant (2012), Ruzicka Preis (2013), and Werner Prize (2016). He is a Clarivate Highly Cited Researcher since 2018. He also serves as an associate editor of the Chemistry of Materials.