10.18.2011

Operation of Light Emitting Diode

Light-emitting diode is a special kind of semiconductor which emits light when current passed through in it.The basic operation operation of light emitting diode (LED) is an follows when the device is forward biased electrons crossed the pn junction from the n type material and recombine with holes in the p type material.
Free electrons are in the conduction band and at a higher energy level than the holes in the valence band.
  Various impurities are added during the doping process to establish the wavelength of the emitted light.The wavelength determines the color of the light if it is visible or invisible.



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