Orange LED in liquid nitrogen

We submerge an orange LED into liquid nitrogen which causes the LED to change colour from orange to yellow and towards green.

• Category

  Science & Technology

[sidewinder4489]

The physical property exhibited in this experiment is known as fluorescence thermochromism. As demonstrated in the video, it is caused by a change in temperature. Typically LEDs work by exciting electrons up into a higher energy state, using an applied electric field. When an electron is initially excited, it can cause the molecule to vibrate, releasing energy. This energy is released as heat. The remaining energy in the electron is then converted to light, as a photon is released.

[sidewinder4489]

However, if the substance is cooled by liquid nitrogen, the initial energy loss from molecule vibrating is reduced (heat is caused by molecular vibrations). This means that there is now more energy that can be converted to light energy, instead of molecular vibrations. This causes the color change because green light has higher energy than orange light. The energy change is small, a difference of 2.051 electon volts for orange light to 2.192 electron volts for green light, but it is noticeable.

[EpicEverythingDude75]

lol the Nitrogen Christmas Light =D

[nextgenhacker01]

HOW THE F DID I GET HERE??

[TCBYEAHCUZ]

so what happens if you do it with a purple led? will it cause it to go UV?

[Andy Kodikonio]

Lol and it's only been one year away from highschool^^

[jedixo]

red is the lowest

[Gordon Gekko]

Violet is the hottest

[hansonsux]

ballast nitrogen

[Andy Kodikonio]

red if i remember correct

[Tim Schmidt]

It's not the band gap changing with temperature? Hmmm?

[jukodebu]

so the color is determined by the amount of energy? What has the highest, white?