Photoelectric Effect
Photoelectric effect is a phenomenon where electrons are ejected from a material when it is exposed to electromagnetic radiation. This occurs when photons, the particles of light, transfer their energy to electrons in the material. This minimum energy required by an electron to leave the surface of the metal is called the work function of the metal(denoted by ϕ0). The minimum frequency of light that can emit an electron from the metal surface is known as threshold frequency and is denoted by v0.
Photoelectric effect was studied experimentally in a vacuum tube, with photoelectrons emitting from the cathode and moving towards the anode. The minimum retarding potential V0 of the anode for which the photocurrent becomes zero is called the cut-off or stopping potential. The energy lost due to this stopping potential is the maximum kinetic energy of the electron.
Photoelectric effect was first successfully explained by Einstein that led him to winning the Nobel Prize in 1921 (not theory of relativity, mind you). The governing equation for all of photoelectric effect is the following
1/2 mνmax2 = eV0 = hν – ϕ0 = h(ν – ν0)
Photon
Photon is a fundamental particle of electromagnetic radiation. It is a quantum of light and other electromagnetic waves. It is the force carrier of the electromagnetic force. Photons can display wave-like behaviors such as interference and diffraction. They can also exhibit particle-like behaviors such as the photoelectric effect. This is known as wave-particle duality.
Photons carry momentum and travel at the speed of light. Photons are produced through processes such as electron transitions in atoms, particle interactions, and particle-antiparticle annihilation. In the photoelectric effect, photons transfer their energy to electrons in a material, leading to the emission of photoelectrons.
Table of Content
- What are Photons?
- How are Photon Produced?
- Difference between Photon and Electron
- Properties of Photon
- Wave-Particle Duality
- Photoelectric Effect