LED vs PN Diode: Intensity & Barrier Potential

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Increasing the forward bias of an LED initially raises light intensity until it reaches a maximum, after which intensity decreases due to excessive current. This drop occurs because exceeding the rated maximum current can damage the LED, leading to reduced light output. The discussion clarifies that an LED is a type of PN diode, but the barrier potential varies among different types of LEDs, with single-color LEDs exhibiting distinct barrier potentials related to their light output frequency. Red, green, and blue LEDs each have different specifications for barrier potential. Understanding these dynamics is crucial for optimizing LED performance in applications.
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when forward bias of led is increased, the intensity of emitted light increases until it reaches a max after which it starts decreasing again...why?
also, in which of the two cases is barrier potential greater, led or pn diode?
 
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pls make u r question more clear... (led is a type of pn diode) so wat do u mean by whose potential (barrier) is greater!
 
i think he mean the intensity of LED increase as current increase, but then if current goes beyond rated max of LED, why the intensity goes down..??

http://en.wikipedia.org/wiki/Light-emitting_diode
 
The light intensity will go to zero if the current gets too high.:biggrin:
 
sphyics said:
pls make u r question more clear... (led is a type of pn diode) so wat do u mean by whose potential (barrier) is greater!

i mean the normal pn diode used in circuits
 
For single color LEDs (not the "white" ones) the barrier potential is coupled to the light output frequency.
If you look at the specs you will find that Red, Green and Blue LEDs have different barrier potentials.
 
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