Distinguished Lecture

Supersonic plasma jets and nanoscale nitride light emitters

Professor Michael J. Gordon
University of California, Santa Barbara

The ability to synthesize a wide range of structured materials, as well as integrate them into larger systems, is fundamental to the development of next-generation micro- and optoelectronic devices, sensors, and energy harvesting and storage technologies. This talk will provide an overview of our research in these areas, with two vignettes focused on microplasma deposition and colloid-based lithography.

In the former, supersonic jet plasma discharges at 10-100 Torr (microplasma jets) are used to spray-deposit nanoparticles, dense layers, and structured thin films of metals (Cu, Ni, Pd) and oxides (CuO, MnO2, RuO2, NiO, FexNi1-xO) on virtually any surface (conductors, insulators, polymers, fibers, and lithographic patterns). Applications include high surface area materials for electrocatalysis, magnetic exchange bias, and supercapacitors. We also use spatially-resolved spectroscopic imaging and Langmuir probe measurements to understand how plasma operating conditions (current, gas, pressure, etc.) affect local gas and electron temperatures in the expanding plasma jet plume.

In the latter venue, we have developed a simple and scalable nanopatterning method based on Langmuir-Blodgett dip-coating of colloids and plasma/photoelectrochemical etching to create moth eye- like patterns and micro/nanoscale features in InGaN/GaN LED and oxide materials to enhance light extraction, reduce strain, realize solution-processable nano-LEDs, and fabricate dielectric meta-surfaces. NanoLED fabrication, PL/EL measurements on light extraction enhancement, reduction of the quantum confined Stark effect due to strain relaxation in InGaN multi-quantum wells, and tunable TiO2 metasurface color reflectors will be highlighted.

Michael Gordon joined UCSB in 2007 and he is currently the Robert G. Rinker Founders Chair Professor in Chemical Engineering and the Vice-Chair for Undergraduate Affairs in the Department of Chemical Engineering. He received his BS/MS in chemical engineering from the Colorado School of Mines, his MS in applied physics and PhD from the California Institute of Technology, and was a post-doctoral fellow at the Laboratoire des Technologies de la Microélectronique (LTM-CNRS) in Grenoble, France. Professor Gordon’s research focuses on synthesis, characterization, simulation, and engineering of nanostructured materials for photonic, energy and chemical conversion applications. He has been recognized for both research and teaching, receiving the NSF Career Award, Packard Fellowship, and Vaughan Lecturership at Caltech, as well as numerous distinguished teaching awards at the campus and department levels.

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