02/09/17 -9:45 AM to 11:00 AM
Dow Lecture Series: Professor Gordana Dukovic
Dow Lecture Series
"Photophysics and photochemistry of nanoscale semiconductors and implications for solar fuel generation"
Colloidal semiconductor nanocrystals are remarkably versatile materials that exhibit a high degree of tunability in electronic structure, optical spectra, and surface properties. My research group is focused on the photophysics and photochemistry of nanoscale semiconductors with a particular emphasis on light-driven reactions involved in solar water splitting. To photochemically drive reduction of H+ to H2, we have coupled CdS nanorods with hydrogenase, a remarkable biological catalyst for H2 generation. Similarly, we have functionalized CdS nanorods with molecular water oxidation catalysts. Using time-resolved spectroscopy over a broad range of timescales (100 fs – 10 μs), we have examined the kinetics of charge transfer between photoexcited nanorods and these redox catalysts and identified structural and chemical parameters that govern the overall photochemical reactivity. The second part of the seminar will focus on nanoscale (Ga1-xZnx)(N1-xOx), a semiconductor that has demonstrated intriguing water splitting activity under visible irradiation. I will discuss the relaxation dynamics of photoexcited states in this material and their implications for solar fuel generation.
Professor Gordana Dukovic
Professor Dukovic's research is focused on fundamental problems in nanoscience and how they impact the application of nanoscale materials to solar energy harvesting. Her group's approach integrates the design and synthesis of novel nanomaterials with detailed electronic spectroscopy in order to reveal how such materials interact with light. The group welcomes a broad spectrum of scientists, with interests ranging from synthetic chemistry to femtosecond spectroscopy.
One of the defining themes in nanoscience is the control of physical properties of a material (such as its electronic structure) through solution-phase synthesis that produces nanostructures of well-defined composition, size, and shape. Dukovic's synthetic efforts are directed at creating complex nanomaterials that incorporate the properties necessary for solar energy applications, such as optimized light absorption and spatial separation of photoexcited charges.
Time-resolved electronic spectroscopy allows the researchers to directly probe the behavior of excited electrons and holes created when a material absorbs sunlight. Events such as charge separation, transfer, recombination, and trapping determine the efficiency of solar energy harvesting. Dukovic's groups is interested in mapping out the dynamics of such events to understand how to improve the design of next generation solar materials.