CELIXS opening online meeting
November 30, 2020
Meeting agenda
10:00 - 10:10 Introduction and opening remarks
10:10 - 10:30 Talk by Y. Hattori, PhD student / Supervisor: Prof. J. Sá
Effect of metal oxide acceptor on gold-plasmon hot electron ultrafast dynamics
Abstract
The recent discovery that metal nanoparticles can generate hot-carriers upon light excitation is seen as a breakthrough in the field of plasmonics and photonics. However, the high expectations for a plasmonic revolution in applications have been dampened by the ultrafast energy dissipation of surface plasmon polariton modes. While research aimed at suppressing loss mechanisms is still pursued, another research direction emerged where charges are harnessed before they relax. Despite the effort, efficiencies of devices based on hot-carriers harnessed from plasmonics are typically very low (few per cent), which somehow paradoxical since efficiencies for electron injection efficiency has been reported to be in the range from 25-40% and hole injection up to 85%. This indicates that the low device performance relates to the undesirable chargeback transfer process, which happens in the picosecond timescale. In this context, we performed a comparative investigation with gold nanoparticles (AuNPs) in direct contact with different metal oxides, namely aluminum doped zinc oxide (Al:ZnO), zinc oxide (ZnO), titanium dioxide (TiO2) and tin oxide (SnO2). Electron dynamics were measured by ultrafast transient infrared absorption technique, which enables us to estimate charge separation and recombination processes in plasmonic-metal oxide composites. The dynamics of injected electrons into the metal oxides and the ultrafast dynamics of AuNPs upon charge transfer will be discussed.
10:30 - 10:40 Questions
10:40 - 11:00 Update on the ELI X-ray spectroscopy end station. Demonstration of recent experimental results by Dr. A. Zymaková
11:00 - 11:30 Discussion