Occurring in the Richardson equation for thermionic emissions, as well of Einstein's photoelectric equation, this is the function that determines the extent to which emissions will occur. It is sometimes expressed as a potential difference symbolized by phi or as the energy 
Occurring in the Richardson equation for thermionic emissions, as well of Einstein's photoelectric equation, this is the function that determines the extent to which emissions will occur. It is sometimes expressed as a potential difference symbolized by phi or as the energy required to remove an electron symbolized by W.
Occurring in the Richardson equation for thermionic emissions, as well of Einstein's photoelectric equation, this is the function that determines the extent to which emissions will occur.
Work function