A plasmon is a quasiparticle that stems from quantisation of oscillations in a plasma or a metal particle. An exciton is a bound state of an electron and an electron hole attracted to each other by electrostatic force. It is the hybrid excitations – the so-called plexcitons – which arise in the intricate interplay between plasmons and excitons that researchers at Lund University and the Izmir Institute of Technology have now investigated. Plexcitons are made of half matter and half light and arise in hybrid nanoscale material, comprising metallic particles and molecular aggregates. Even though the efforts on achieving better understanding of them have been going for more than ten years, there has been no breakthrough. However, in a new study presented in the research journal Chem, the Swedish-Turkish research team has presented revealing results.
“We have studied behaviour of the plexcitons all the way from absorption of photons until their energy is dissipated as heat”, says Donatas Zigmantas, Professor of Chemistry at Lund University.
Together with his researcher colleagues Daniel Finkelstein-Shapiro, first author of the study and currently assistant professor at the National Autonomous University of Mexico, Zigmantas carried out a highly-advanced spectroscopy experiments in Lund and then succeeded in mapping the plexcitons’ unique properties.
“The plexcitons are very interesting because they possess features that neither molecules nor semiconductors have. An increased understanding will make it easier for future researchers to manipulate their properties and utilise photoexcitation energy over longer period of time”, says Daniel Finkelstein-Shapiro.
Plexcitons have been suggested as a future material for applications such as quantum information processing, photocatalysis and photonics on a nanoscale. An improved understanding of what happens when plexciton particles absorb photons facilitates the development of these and completely new applications.
“It is difficult to predict where plexcitons will contribute to the societal needs in the future. Perhaps through photocatalysis applications they will help to reach sustainable development goals as defined by the United Nations”, says Donatas Zigmantas.