Einstein explained the photoelectric effect by postulating that, in a photon, the energy was proportional to the frequency: Note that we will typically express the energy of electrons in "electron Vol...Einstein explained the photoelectric effect by postulating that, in a photon, the energy was proportional to the frequency: Note that we will typically express the energy of electrons in "electron Volts (eV)‟. The SI unit for energy, the Joule, is typically much too large for convenient discussion of electron energies. Figure \(\PageIndex{17}\): The wavelength shift of light after collision with an electron is consistent with a transfer of momentum from a photon to the electron.
The energy required to promote an electron from the Fermi level in the contact to the vacuum energy is defined as the work function (\(\Phi\)). Although the assumption of equilibrium within the contac...The energy required to promote an electron from the Fermi level in the contact to the vacuum energy is defined as the work function (\(\Phi\)). Although the assumption of equilibrium within the contact cannot be exactly correct if a current flows through it, the large population of mobile electrons in the contact ensures that any deviations from equilibrium are small and the potential in the contact is approximately uniform.
