If one emits a light beam in a given frequency (obviously there is a threshold frequency) over a metal plate, even on low energies, some electrons could be ejected and one could been measuring an electrictal current, briefning these results agrees with Einstein's Nobel's Prize. The question is (in a few words), if one emits a electrons beam over a surface, with some energy who I don't even know the threshold, could exist a light beam (in any frequency of electricmagnetic spectrum) emitted from that surface (metallic or non)?


Yes, indeed! It’s called cathodoluminescence.

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  • $\begingroup$ Greetings, I agree, but it could work in any surface even impacting on a non luminescent? $\endgroup$ – Christyan Condé Aug 17 '19 at 18:49
  • $\begingroup$ @ChristyanCondé If the material is non luminescent, the energy of the electron will go to some other excitation, such as heat. So you wouldn’t get light. $\endgroup$ – Gilbert Aug 17 '19 at 19:09
  • $\begingroup$ I agree again, but even heating a surface is a kind of emit light. I realy don't know if this question may be answered but this is part of them! $\endgroup$ – Christyan Condé Aug 17 '19 at 19:19
  • $\begingroup$ @ChristyanCondé essentially, when you inject electrons into a material they have excess energy and need to relax. How they relax depends on the material. Some emit light, some excite plasmons, some excite phonons, etc. $\endgroup$ – Gilbert Aug 17 '19 at 19:20
  • $\begingroup$ Ok by now, the closer answer of what I think about the electron nature, but the second part is, this means the reversibility of photoelectric effect? $\endgroup$ – Christyan Condé Aug 17 '19 at 19:26

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