Professor Jonathan Owen
Etter Memorial Lectureship
Department of Chemistry
"The mechanisms governing colloidal Quantum Dot size and size distributions"
The size and shape homogeneity of modern colloidal semiconductorbnanocrystals or ‘Quantum Dots’ (QDs) result in their characteristically narrow photoluminescence linewidths. This narrow and tunable luminescence is driving the cutting edge in display technologies and can increase the luminous efficacy of commercially viable solid state lighting devices by > 25%. The spectral tunability and linewidth are due to the extraordinary size and size distributions achievable using modern colloidal synthesis. Despite many years of research in that regard, however, the optimization of QD luminescence remains an empirical process of trial and error. Accurate mechanistic pictures that can be used to design improved syntheses are lacking. To address this discrepancy our group studies the kinetics of colloidal nanocrystal nucleation and growth using in situ x-ray scattering and optical absorption methods. We have demonstrated the surprising finding that size and size distributions are primarily governed by the reactivity of nanocrystals toward monomer attachment rather than the conventional
"burst of nucleation" and diffusion limited growth hypothesis that has dominated synthetic design for the last 40 years.
Jonathan Owen obtained a BS from the University of Wisconsin-Madison in 2000, a PhD from Caltech in 2005 and was a postdoctoral researcher at UC Berkeley until 2009. In 2009 he joined the faculty at Columbia University where he is currently Associate Professor of Chemistry. His group studies the coordination chemistry of colloidal semiconductor nanocrystals, as well as the mechanism of nanocrystal nucleation and growth. He has received several awards for his work including: The 3M Nontenured Faculty Award (2010); The Early Career Award from the Department of Energy (2011); The DuPont Young Faculty Award (2011); A Career Award from the National Science Foundation (2012); The Award in Pure Chemistry from the American Chemical Society (2016)