A Clear LED emitting different coloured light?

[Johnahh]

Am I right in thinking the chip controlling the LED is applying more or less power to make electrons go to different energy levels to emit different colours of light?
If anyone could clear this up for me it would be much appreciated.

 

[Integral]

The color of an LED is determined by the properties of the chip producing the light, not the color of the plastic cover.

 

[Johnahh]

Thanks for the reply but what properties affect the colour? I was after the fundamentals of how the LED works.
Thanks

 

[AlephZero]

The basic property is the band gap in the semiconductor material that the LED is made from. Multi color LEDs have several LEDs made from different materials inside one package. Each one has a fixed color, but the brightness can be varied by controlling the current through it.

This is the same principle as the way computer or TV displays work, by changing the brightness of the red green and blue components of the light to produce the effect of any color.

To fully understand how this works, you also need to know how the eye (and brain!) detects the light and "decides" what color it is.

 

[Bobbywhy]

For an excellent explanation of the semiconductor materials that determine the color of the LED, see:

http://en.wikipedia.org/wiki/Light-emitting_diode