The work function of a metal is the minimum amount of energy required to start the emission of electrons from the metal’s surface.
The work function is the minimum amount of energy required to remove an electron to infinity from a given metal’s surface. The threshold frequency is the minimum frequency of the incident light, which can cause the ejection of electrons without giving them additional energy.
- The work function can be measured with PES (photoemission spectroscopy) and Kelvin probe (KP).
- While PES allows the absolute work function measurement, KP only gives the contact potential difference (CPD) between the actual probe and the sample surface.