Chemical Society Seminar: Zachary Hudson - High-Performance Luminescent Materials Using Structural Constraint
Abstract:
Stability under excitation is critical to nearly all applications of luminescent materials. Nonradiative decay pathways that cause photobleaching or decomposition limit the usefulness of organic semiconductors in electronics, bioimaging, and photocatalysts. Here we describe new pi-conjugated systems with locked planarity designed to limit nonradiative decay. We use s-heptazines and imidazoacridines as strong electron acceptors, and azatriangulenes as electron donors to give materials exhibiting thermally activated delayed fluorescence (TADF), room-temperature phosphorescence, and two-photon absorption. These materials exhibit reduced photobleaching, large two-photon cross-sections and photoluminescence quantum yields near 100%. We also use scanning tunneling microscopy on Ag(111) to probe the electronic interactions of these materials on surfaces. This lecture will also describe the use of high-performance TADF materials in luminescent nanoparticles for bioimaging, and as photocatalysts for high-energy organic transformations useful to drug discovery campaigns.
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Bio:
Zachary M. Hudson is an Associate Professor and Canada Research Chair in Sustainable Chemistry at the University of British Columbia. Zac completed his B.Sc. at Queen’s University in Kingston, Ontario. He remained at Queen’s to pursue a Ph.D. in Inorganic Chemistry with Prof. Suning Wang, also holding graduate fellowships at Jilin University in China and Nagoya University in Japan. He then moved to the University of Bristol as a Marie Curie Postdoctoral Fellow with Prof. Ian Manners, followed by a second Postdoctoral Fellowship at the California Nanosystems Institute at the University of California, Santa Barbara with Prof. Craig Hawker. He joined the faculty at UBC in 2015, where he holds the Canada Research Chair in Sustainable Chemistry. His research program develops luminescent materials for optoelectronics, bioimaging, and photocatalysis. Recent awards for his work include the ACS Herman Mark Award in Polymer Science, the Polymer International IUPAC Award, and most recently the Charles McDowell Medal for UBC’s top researcher under 40 in science and engineering.