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Cause of LED Efficiency Droop Finally Revealed

An anonymous reader writes "Researchers from the University of California, Santa Barbara, in collaboration with colleagues at the École Polytechnique in France, have been able to prove the theory behind LED 'droop.' LED droop is the term for how LEDs emit less light when the amount of current being pushed through them goes above a certain level. 'The cost per lumen of LEDs has held the technology back as a viable replacement for incandescent bulbs for all-purpose commercial and residential lighting.' Now that we understand what causes this, we should start to see research go into technology to circumvent LED Droop. 'LEDs have enormous potential for providing long-lived high quality efficient sources of lighting for residential and commercial applications. The U.S. Department of Energy recently estimated that the widespread replacement of incandescent and fluorescent lights by LEDs in the U.S. could save electricity equal to the total output of fifty 1 GW power plants.'" A pre-print of the team's paper is available at the arXiv.

9 of 308 comments (clear)

  1. multiply by Randle_Revar · · Score: 5, Insightful

    >the total output of fifty 1 GW power plants

    Soooo... 50 GW?

    1. Re:multiply by Anonymous Coward · · Score: 5, Funny

      Witch!

      Don't you come in here and git all European-like and start a-quotin' your Systeme Internationale at me. I likes my units in New Imperial, and thats how's they're gonna stay if I done have anything to done say abouts it.

    2. Re: multiply by Anonymous Coward · · Score: 5, Funny

      Great Scott!!! 50 Jiggawatts!?!

    3. Re:multiply by conorpeterson · · Score: 5, Funny

      >the total output of fifty 1 GW power plants

      Soooo... 50 GW?

      Or by my own calculation, 41.32 lightning bolts! Great Scott!

  2. Answer not in summary by Anonymous Coward · · Score: 5, Informative

    It's because of Auger recombination. Basically, you stick in too many electrons, and they all mill around talking with each other instead of getting any work done. This is also known as the 'Water Cooler Effect'.

    1. Re:Answer not in summary by N+Monkey · · Score: 5, Funny

      So, you're saying that instead of an electron falling into a hole causing a photon to be given off, the electrons are all huddled together elsewhere talking about the last episode of Big Bang Theory?

      No. They'd be discussing "Quantum Leap"

  3. Re:Darn by Anonymous Coward · · Score: 5, Funny

    Of course we would. We all have time machines.

  4. Since my comment is in the other less-popular post by Khyber · · Score: 5, Interesting

    Pay very close attention to LEDs. Now that we've identified the root cause of one of our biggest problems, in a few years, we'll find ways to work around those problems and extend the lifespan of an LED (and output at higher drive currents) with a minimal loss of light.

    This is EXCITING news, as the uses for this across the entire electronics industry are MASSIVE. Higher-efficiency, longer-lasting LEDs means better optical devices and such, as this same tech can be applied down into solid-state laser diodes.

    I'm literally about to piss myself from this news. The sheer implications of this knowledge are astounding.

    I hope thermal pad and PCB makers are paying attention and prepare, because very soon we'll be pushing a LOT more power through these tiny LEDs, and we'll need the local cooling to compensate.

    I only wonder just how far they can defeat or mitigate this effect, and how. Thicker well walls might be an idea, or perhaps a nano-wire-like growth pattern, like we've seen with the recent development of microwires on graphite sheets, can increase the surface area and reduce the available recombination area, thus forcing electron transport.

    Something to either attract, guide, or force more electrons across the gap seems to be what is needed.

    --
    Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
  5. Re:but won't somebody think of the Mercury? by __aajfby9338 · · Score: 5, Funny

    LED's don't emit radio waves.

    Then you should take them back to the store for a refund.