Nobel Prize for physics goes to inventors of low-energy LED light

[wantone]

http://www.msn.com/en-us/news/technology/nobel-prize-for-physics-goes-to-inventors-of-low-energy-led-light/ar-BB7ZUAE

[hossners]

Their contribution was the last elusive piece to produce energy efficient White (Red + Green + Blue) light! (Green and Red LEDs were common at the time)
KUDOS!
http://www.washingtonpost.com/news/speaking-of-science/wp/2014/10/07/the-nobel-prize-in-physics-goes-to-three-men-who-gave-us-blue-light-emitting-diodes-used-daily-in-your-smartphone-screen/

Steve in OR

:yes:

[MarcPW]

Japaneses inventors/scientists. And that's where I went a few weeks ago... My Speedy Marie (F6B) will soon be gorgeous !

9035

[srt8-in-largo]

Didn't Obama receive a Nobel prize, the Peace prize. WHYYYY????

These guys actually did something to deserve it.

[Jim]

I agree, in my 67 years I have never seen the country in such a sorry state, and the world in such chaos. It really worries me, but all I can do is vote, ride, and take care of my family as best I can. Please wake up America!!!

[MarcPW]

I agree, in my 67 years I have never seen the country in such a sorry state, and the world in such chaos. It really worries me, but all I can do is vote, ride, and take care of my family as best I can. Please wake up America!!!

Thanks president Bush, his administration, his cronies for all the lies, but keep defending the 2nd amendment and completely ignoring the
1st one as only information (a free one, under freedom of information, not current in the US as we speak) would have made his actions impossible... And Obama has now ruined the internet one too... :banghead:

[wantone]

Thanks!!! I'm glad u moved this thread. I wanted it to become more of a technical info thread but looks like it turned into political info.

[MarcPW]

Thanks!!! I'm glad u moved this thread. I wanted it to become more of a technical info thread but looks like it turned into political info.

Sorry Wantone :039:

[srt8-in-largo]

Thanks!!! I'm glad u moved this thread. I wanted it to become more of a technical info thread but looks like it turned into political info.

Oops, yeah sorry man.

It's pretty amazing to think that LED's have only been around since about 1990. The reason why LED's consume so little power is because the light is produced in a non-conductive medium. That is, the light is not generated from electricity being conducted; it requires a voltage, yes,... but very little current.

Metals are constructed of molecules that have an excess of free electrons. By some measures this is in fact the definition of a metal; a material that is essentially a sea of free electrons. When a voltage is applied, the electrons are free to move, and they do so; moving from the positive to the negative voltage terminal. If enough electrons are moved fast enough, the particle motion creates heat, and eventually the heat becomes great enough to become visible. Bulb filaments are special metals... designed to heat quicker in order to produce visible light. The downside is it takes a lot of energy to make the electrons move... and virtually all of this energy is converted into heat, with light essentially only being a byproduct.

LED's, on the other hand, are constructed out of what's called semi-conductor material. The molecules in semiconductor material are rigidly held in place in a lattice network and, as such, there are no free electrons. We can contaminate semiconductor material in such a way to create a few missing electrons or a few excess electrons; this is called doping and results in the creation of n-type or p-type semiconductors, respectively. When you join an n-type and p-type semiconductors... you have just created this wonder of the modern world... the LED.

When you apply a voltage across the ends of an LED it causes the few excess electrons in the p-type to break away from their molecules and they begin traveling to the n-type side that is connected to the negative terminal. When that electron "jumps" the p-n junction, a complicated change in atomic energy states occurs, and a byproduct of this change in energy states is the release of a photon. So, with very little movement of electrons, and therefore very little heat generation, we can produce light. Changing the doping and the materials will cause photons of different wavelengths to be emitted, and now we can create LED's in a variety of colors.


The p-n junction also forms the basis of the millions of nano-scale transistors that make up the processor in your computer that allows us to communicate instantly world-wide. Really... I mean, REALLY... the Nobel prize should have been given to the folks who first discovered and understood the workings of the p-n junction. If it weren't for THESE folks, modern computers, much less LEDs, would not exist. I'm sure that is somehow Bush's fault too :icon_biggrin:

[Phantom]

Str8-n-largo, that's a nice explanation,
LED's have been around for a long time, at least since the late 60's - early 70's

I was experimenting with LED's in my High school electronics class back in 1981.

Playing with resistors, blowing up capacitors, popping diodes and creating circuit boards was part of the fun.
For those that don't know .... LED is the abbreviation for Light Emitting Diode.

[srt8-in-largo]

Oops, you're right. How did I get 1990 stuck in my head.

I would venture a guess to say that the low-current aspect of LED's is one of the reasons there have been stumbling blocks in trying to create really really bright LED's... but I'm not up to speed on that and could be wrong.