- Cathodoluminescence (CL) is the emission of photons of characteristic wavelengths from a luminescent material that is under high-energy electron bombardment.
- This is achieved by exciting an electron out of the valence band into the conduction band, which subsequently leaves an electron hole in the valence band.
- The excited electron in the conduction band will subsequently drop down into the valence band to fill the e- hole.
- This decrease in energy will cause a photon (γ) to be released as visible light, ultraviolet or infrared, which can be detected by a CL detector.