Fig. 1: Challenges in achieving single-particle CL imaging at the nanoscale.
From: Multicolor cathodoluminescence imaging of single lanthanide nanoparticles
a Secondary electron (SE) and CL signal collected from single LNPs in samples containing either NaHoF4 or NaDyF4 LNPs. Ensemble CL spectra of the LNPs and transmission bands of optical filters (shaded bands) used in CL imaging are also shown. b Observed brightness of NaHoF4 LNPs as a function of their size. c Simulated dependence of CL signal on NaHoF4 LNP size at 3 keV electron beam energy. Energy absorbed by the nanoparticles was used as a proxy for CL brightness. The interaction volume of the electron beam inside nanoparticles of different diameters (ø), 15, 20, and 30 nm, is also shown. Colormap shows the normalized electron density. d SE and CL signals collected from a single LNP in a sample containing both NaHoF4 and NaDyF4 LNPs. e Illustration showing the origin of nonlocal CL signal due to stray electrons originating from the excited LNP. Scale bars: a, c, d 20 nm. Pixel intensity scaling: a 300–1400 photons s−1, d 300–800 photons s−1. Source data are provided as a Source Data file.
