• DOI:10.1126/sciadv.abq4947
• Corpus ID: 247154741

Cathodoluminescence excitation spectroscopy: Nanoscale imaging of excitation pathways

@article{Varkentina2022CathodoluminescenceES,
  title={Cathodoluminescence excitation spectroscopy: Nanoscale imaging of excitation pathways},
  author={Nadezda Varkentina and Yves Auad and Steffi Y. Woo and Alberto Zobelli and Laura Bocher and Jean-Denis Blazit and Xiaoyan Li and Marcel Tenc{\'e} and Kenji Watanabe and Takashi Taniguchi and Odile St{\'e}phan and Mathieu Kociak and Luiz Henrique Galv{\~a}o Tizei},
  journal={Science Advances},
  year={2022},
  volume={8}
}

• N. Varkentina, Y. Auad, +10 authors L. Tizei
• Published 25 February 2022
• Physics, Chemistry
• Science Advances

Following optical excitations’ life span from creation to decay into photons is crucial in understanding materials photophysics. Macroscopically, this is studied using optical techniques, such as photoluminescence excitation spectroscopy. However, excitation and emission pathways can vary at nanometer scales, preventing direct access, as no characterization technique has the relevant spatial, spectral, and time resolution. Here, using combined electron spectroscopies, we explore excitations’ creation and decay in two representative optical materials: plasmonic nanoparticles and luminescent two-dimensional layers. The analysis of the energy lost by an exciting electron that is coincident in time with a visible-ultraviolet photon unveils the decay pathways from excitation toward light emission. This is demonstrated for phase-locked (coherent) interactions (localized surface plasmons) and non–phase-locked ones (point defect excited states). The developed cathodoluminescence excitation spectroscopy images energy transfer pathways at the nanometer scale, widening the available toolset to explore nanoscale materials.