Search This Blog

1 March 2019

Difference between photodiode and LED

The major difference between the photodiode and LED is that, photodiode work on the principal of the photoconduction while LED operates on the principle of electro-luminance.  This post gives information about photodiode and LED to know more details about the topic.

Photodiode:
  • A photodiode is a light detecting device.
  • A photodiode is a two terminal device which can convert light into electrical energy.
  • Photodiode work on the principle of photoconduction.
  • Photodiode must be used germanium and silicon semiconductor used.
  • It works only reverse bias mode.
  • A photodiode is used in fiber optic communication, fluxmeter up to a couple, etc.
  • Reverse saturation current is significant so dark current flow when no light rays are incident on it.
  • Photodiode must be used switching, high-speed counting, AC coupled signaling, etc.
LED :
  • LED has a light emitting diode.
  • LED is a two terminal device which can convert electrical energy into light energy.
  • LED is work on the principle of electro-luminance.
  • Gallium Arsenide or Gallium phosphide semiconductor used.
  • It works only forward biasing mode.
  • LED generated radiated power due to change in temperature.
  • LED has no leakage current.
  • The LED must be used indicator in AC circuit, Alphanumeric and numeric.
A key difference between photodiode and LED:
  • We all know that photodiode is a light detecting device while LED is a light-emitting diode.
  • LED and photodiode both are two-terminal devices.
  • Photodiode work on reverse biased, LED work on forwarding bias.
  • The major difference is that the photodiode works on the principle of photoconduction while in when we are using LED it to work on the electro-luminance.
  • Photodiode converts light energy into electrical energy and on the other hand LED converts electrical energy into light.
  • A photodiode is made for germanium and silicon semiconductor whereas LED is made for GaAsp or GaP.
  • Photodiode provides energy to electron and holes by exposing itself towards light radiation however LED  emits photons due to electron-hole recombination.
Explore more information:

Posted by on