How does quantum theory explain the working of a photocell?

Each photon of light with a certain minimum energy releases an electron from an atom.

Explanation:

A photocell works on the principle of photoelectric effect. A proton is taken to have a particle nature hence photons have to interact with electrons.In this particular experiment, photons have energy greater than the work function of the metal and thus ejects electrons from the plate.

the device is called “ rocket engine”