Nobel Prize in Physics for blue LED

Discussion in 'Off-Topic' started by MrChips, Oct 13, 2014.

  1. MrChips

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    Oct 2, 2009
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    Nobel Prize in Physics awarded to three Japanese scientists.

    While I will not get into an argument over the merits of the blue LED vs red or any other colour,
    here are some points why the creation of the blue LED and hence white lighting is revolutionary according to Professor Emeritus Christopher Hall, Centre for Materials Science and Engineering, University of Edinbugh:

    http://www.cbc.ca/day6/blog/2014/10/09/post-6/

    1. Brings lighting to many communities in the world that have no electricity grid.

    2. Low energy consumption

    3. Blue LED paves the way for UV and ultra-UV LED which can be used for such things as water purification.

    4. White LED lighting can be used for Li-Fi transmission superimposed on top of regular room illumination.

    This brings an alternative to short range bluetooth transmission.

    And this brings another closer meaning to the word "bluetooth" which is originally named after King Harald Bluetooth of Denmark.
     
    Last edited: Oct 13, 2014
  2. ScottWang

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    Aug 23, 2012
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    Although the blue LEDs are very useful, but what I concerned was that the UV will make our eyes to get Cataract, that's too bad.
     
  3. nsaspook

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  4. GopherT

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    The fact that it is blue didn't mean the technology from 1972 was a commercially viable option - especially for high brightness (efficiency), high power, blue. In fact, it wasn't. Not even close to a solution that would impact downstream applications. The multiple layers of modern LEDs were really a recent discovery made possible by the availability of high purity trimethyl gallium (6N and better) and high purity ammonia (7N and better).
     
  5. nsaspook

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    All that is true if the reason for giving a Nobel prize in Physic is the commercialization of basic research and science.
    What patent from 1973 is referenced for most of these advances?
    http://www.google.com/patents/US3819974#forward-citations
    http://semiengineering.com/who-really-invented-the-blue-led/

    http://www.eetimes.com/author.asp?section_id=36&doc_id=1324275&_mc=RSS_EET_EDT
     
    Last edited: Oct 15, 2014
  6. GopherT

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    From the Nobel site

    "for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources".

    I have no idea how the 1973 invention related to the winners' discoveries other than the emitted color.
     
  7. nsaspook

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    The basic GaN process as detailed in the patent with magnesium doping is the basis for almost all blue LEDS including the 'efficient' ones. I don't have a problem with the winners of the prize, they do deserve it if those are the rules of the prize but IMO "invention of efficient" is 90% good engineering not physics after the basic principles are discovered.
     
    Last edited: Oct 15, 2014
  8. GopherT

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    Magnesium is indeed old technology. Apparently why it is not the key dopant for the Nobel winner - it is used to make the pGaN layer. The recent LED technology uses a GaN/InN alloy as tuned band gap material as a MQW layer (micro-quantum well). It is possible to have several MQW layers. GaN/InN alloy band gaps from 0.7 (IR) to 3.4 eV (UV) can be tuned with only Trimethylgallium, trimethyl indium and ammonia in a CVD tool.

    Maybe this achievement would have been better for the chemistry category rather than physics.

    Trimethylindium, one of four high purity organometallics needed for the GaN LEDs, has only been available commercially for the past 12 years or so.

    The only indium mention in the original patent is in the solder for the wire bonding.
     
    Last edited: Oct 15, 2014
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