Materials Science Research Lecture

Wednesday February 20, 2019 4:00 PM

Hybrid Organic-Inorganic Materials from Nanoscale to Bulk: Assembly, Properties, and Applications in Optoelectronics and Renewable Energy

Speaker: Osman Bakr, Materials Science and Engineering, KAUST (Saudi Arabia)
Location: Noyes 147 (J. Holmes Sturdivant Lecture Hall)

Abstract: Hybrid organic-inorganic materials are often comprised of building-blocks that have the potential for directional interactions. Those interactions could be exploited to control the dimensionality and connectivity of the building-blocks with major consequences for the material's physical and chemical properties. Our group explores two such classes of hybrid materials: hybrid metal halide perovskites and atomically precise metal nanoclusters.

Metal halide perovskites exhibit a broad range of photophysical and optical behavior depending on their crystallinity, dimensionality, and composition, which makes them ideal for exploring fundamental optoelectronic phenomena and applications. Here I discuss our efforts in growing and understanding the properties of bulk and nanoscale monocrystalline perovskite and perovskite-derived materials. The synthesis, surface defect-passivation, and integration of these materials in a wide range of optoelectronic applications are demonstrated, including: high-performance single-crystal perovskite solar cells; simultaneously fast and sensitive photodetectors; x-ray imaging and scintillation; visible-light communication; light-emitting diodes; and artificial multiple quantum well heterostructures.

Nanoclusters are atomically precise nanoparticles, i.e. homogeneous in size and composition. Their precise nature makes them highly prized in the nanochemistry toolkit, as they open up nanoparticles (and their ensuing applications) to the tools of supramolecular assembly, property control, and materials interrogation (e.g. single-crystal x-ray diffraction), in addition to well-defined computational modelling. I describe strategies that we developed for atomic-level control over the electronic structure, surface chemistry, and self-assembly of metal nanoclusters with a particular emphasis on silver and copper clusters. Atom-precise doping, ligand-exchange, and reticular chemistry approaches are utilized to create conceptually new cluster-based materials compositions, building-blocks, and assembled frameworks that have a non-trivial impact on the crystal structure, reactivity, and optical behavior.

More about the Speaker: Osman M. Bakr is an Associate Professor of Materials Science and Engineering at KAUST, Saudi Arabia. He earned a B.Sc. in Materials Science and Engineering from MIT (2003) as well as an M.S. and a Ph.D. in Applied Physics from Harvard University (2009). His research group works on the design and self-assembly of hybrid and inorganic materials to generate breakthrough applications in solar energy harvesting, photonics, and optoelectronic devices. His group has been at the forefront of the synthesis, property elucidation, and applications of two major classes of materials: lead halide perovskites and atomically precise noble metal nanoclusters. Bakr published over 142 articles in international peer-reviewed journals (including 27 Thomson Reuters™ Highly Cited Papers), 137 of which as an independent faculty member.

Bakr was selected as a Young Scientist by the World Economic Forum (2016); and as a member of the Editorial Advisory Boards of ACS Energy Letters (2016) and Chemistry of Materials (2017). He was awarded the SABIC Endowed Presidential Career Development Chair (2013); the Innovator Under 35 Award in the Arab World by the MIT Technology Review- Arab Edition (2016); and The King's Award for Inventors and the Gifted (2018). In 2018, he was ranked by the Times Higher Education as among the top 10 university researchers world-wide in the area of "perovskite solar cells".
Bakr is co-founder of Quantum Solutions Inc., currently a leading manufacturer of quantum dots for optical sensors and next-generation QD-based display technologies.

Series Materials Research Lecture Series

Contact: Jennifer Blankenship at 626-395-8124 jennifer@caltech.edu