The Photoelectric Effect: Basics (Cambridge (CIE) A Level Physics): Revision Note

The photoelectric effect: basics

The photoelectric effect

• The photoelectric effect is the phenomenon in which electrons are emitted from the surface of a metal upon the absorption of electromagnetic radiation

• Electrons removed from a metal in this manner are known as photoelectrons

• The emission of photoelectrons is known as photoelectric emission

• The photoelectric effect provides important evidence that light is quantised

  • Each photon has energy hf, and each electron can absorb only a single photon

  • An electron is emitted only if hf is at least the work function $\Phi$, so there is a minimum (threshold) frequency $f_0=\frac{\Phi }{h}$, whatever the intensity

The photoelectric effect

Photoelectrons are emitted from the surface of metal when light shines onto it