Cathodoluminescence (CL) - is the emission of light as a result of the interaction of a material with the electron beam. CL spectrometer and detector in SEM can be used to characterize the composition, optical and electronic properties of materials. A CL spectrometer and detector (Gatan MonoCL4 Elite) is installed on Gemini SEM. CL signal can be easily detected for direct band gap semiconductor materials, but it’s not limited only to that group of materials. It is widely used in geological and archeological sciences due to the strong emission of calcite and Quartz defects bands. In materials science we have measured perovskites both in bulk and nanoscale forms as well as other nanoscale materials. Occasionally the nanomaterials are cooled down to -140°C using the cryo stage to enhance the CL signal.

References

• Luminescence reveals variations in local structural order of calcium carbonate polymorphs formed by different mechanisms. Michael B. Toffolo, Giulia Ricci, Luisa Caneve & Ifat Kaplan-Ashiri. Scientific Reports volume 9, Article number: 16170 (2019)
  https://doi.org/10.1038/s41598-019-52587-7
• Large lattice distortions and size-dependent bandgap modulation in epitaxial halide perovskite nanowires. Eitan Oksenberg, Aboma Merdasa, Lothar Houben, Ifat Kaplan-Ashiri, Amnon Rothman, Ivan G. Scheblykin, Eva L. Unger & Ernesto Joselevich. Nature Communications volume 11, Article number: 489 (2020)
  https://doi.org/10.1038/s41467-020-14365-2
• Cathodoluminescence in single and multiwall WS₂ nanotubes: Evidence for quantum confinement and strain effect. S. Ghosh, V. Bruser, I. Kaplan-Ashiri, R. Popovitz-Biro, S. Peglow, J. I. Martınez, J. A. Alonso & A. Zak. Applied Physics Reviews 7, 041401 (2020)
  https://doi.org/10.1063/5.0019913