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Ultrasensitive probing of plasmonic hot electron occupancies

Hungarian researchers have made significant progress in examining the properties of the so-called hot electrons found in metals. In the future, their results can be used in important areas such as the development of solar cells and nanoscale circuits, and the improvement of the sensitivity of various sensors.

Ultrasensitive probing of plasmonic hot electron occupancies

 

Authors of the article

ELI ALPS, Szeged - Judit Budai, Zsuzsanna Pápa & Péter Dombi

Department of Optics and Quantum Electronics, University of Szeged - Judit Budai

Wigner Research Centre for Physics, Budapest - Zsuzsanna Pápa & Péter Dombi

Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest - Péter Petrik

 

Abstract

Non-thermal and thermal carrier populations in plasmonic systems raised significant interest in contemporary fundamental and applied physics. Although the theoretical description predicts not only the energies but also the location of the generated carriers, the experimental justification of these theories is still lacking. Here, we demonstrate experimentally that upon the optical excitation of surface plasmon polaritons, a non-thermal electron population appears in the topmost domain of the plasmonic film directly coupled to the local fields. The applied all-optical method is based on spectroscopic ellipsometric determination of the dielectric function, allowing us to obtain in-depth information on surface plasmon induced changes of the directly related electron occupancies. The ultrahigh sensitivity of our method allows us to capture the signatures of changes induced by electron-electron scattering processes with ultrafast decay times. These experiments shed light on the build-up of plasmonic hot electron population in nanoscale media.

 

The full article published in Nature is available by clicking here.

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