 Work function

The work function is the minimum energy needed to remove an Electron from a solid to the nearby vacuum level. A junction's effective barrier need not equal either electrode's isolated work function.

The work function is a concept in physics and materials science that refers to the minimum amount of energy required to remove an electron from the surface of a solid material, typically a metal. It is a critical parameter in fields such as semiconductor physics, photoelectric effect studies, and electron emission phenomena.