Photocell works on the principle of photoelectric effect.
The photocell is a device that uses the photoelectric effect to operate. A photocell is a device that transforms light energy into electricity. The photons with suitable frequency will remove electrons from the metal surface.
The photoelectric effect is a phenomenon in which electrons are ejected from the surface of a metal when light is incident on it. These ejected electrons are called photoelectrons. It is important to note that the emission of photoelectrons and the kinetic energy of the ejected photoelectrons is dependent on the frequency of the light that is incident on the metal’s surface. The process through which photoelectrons are ejected from the surface of the metal due to the action of light is commonly referred to as photoemission.