Thermionic emission involves heat energy to excite the electron and remove it. In the photoelectric effect, a beam of light is involved.

As per my understanding heat and photons, both are energy. Heat is transferred through electromagnetic waves and light is also an electromagnetic wave which means both types of emission are of the same type.

Where I'm wrong in understanding the concepts? How both emissions are different?


1 Answer 1


Photoelectric emission occurs when a photon of frequency more significant than a threshold value (i.e., having sufficient energy) hits a metal surface. In contrast, thermionic emission is caused when the metal is heated. In both processes, the electrons are emitted, but the cause is different.


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