- How can explain the difference of these red dots?
- Red line = Green line ?. How to explain it?
Thank you so much.Even when the applied voltage is zero, there is a kind of "virtual" voltage that pulls the electrons back into the metal. This is called the "work function", I believe.
So at low photon frequencies, there is a smaller chance that an electron will end up with enough energy to leave the metal (because total energy = photon energy + random thermal energy). For high photon energies, there is more chance of escaping i.e. more chance that electron's original thermal energy plus photon energy will carry it over the work function threshold.