Observation of surface plasmon excitation/relaxation processes of nanoparticles

Summary In a joint research project, a research group including Dr. Shota Kuwahara from the Faculty of Science, Toho University, successfully investigated relaxation processes using energy loss peak intensities, positions, and widths in electron energy loss spectroscopy with a picosecond-pulsed electron probe. Using this method, the relaxation times of photoexcited nanoparticles were measured and from that the temperature change over time was successfully estimated. Thus, energy-loss spectroscopy using pulsed electron beams was adapted and applied to plasmonic materials. This study presents the realization of a new time-resolved nano-measurement system through an industry-academia collaboration. It is also expected to be adapted to the measurement of optical energy conversion processes of plasmonic materials and the localized thermal relaxation nano-measurement of thermoelectric conversion materials. The results of this research were published in the scientific journal Applied Physics Letters on 6 October 2022.