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EL Material Can Generate Both Red and Green Light

Posted by timothy on from the stop-no-go-no-stop dept.

Burstwave writes "According to this story, investigators at Philips, in collaboration with researchers at the University of Amsterdam, have developed the first electrochemiluminescent material that can generate both red and green light, an effect that depends on current flow. The full report will appear in Nature on Monday. This significant advance in ECL technology will lead to smaller and brighter full-color LED displays."

21 comments

  1. Report from amsterdam. by Anonymous Coward · · Score: 3, Funny

    The scientists are reported to have said "whoa, look at the colours!!"

  2. Spanish-speaking? by agdv · · Score: 3, Funny

    Ok, who else thought this was about something in Spanish, reading "el material"?

  3. And As Usual... by Cyno01 · · Score: 3

    Blue lags behind. Whats with that? Blue LEDs, blue Lasers, Blue OLEDs, all took so much longer after green ones compared to green ones after red ones.

    --
    "Sic Semper Tyrannosaurus Rex."
    1. Re:And As Usual... by joebp · · Score: 2, Informative
      Blue wavelength < Red wavelength

      Shorter wavelengths are significantly harder to produce using *LED technology because the... [should have listened in Physics classes].

    2. Re:And As Usual... by Anonymous Coward · · Score: 0

      blue.. higher energy.. mumble mumble. electrons, band gaps, something.

    3. Re:And As Usual... by Mathness · · Score: 1

      Blue EL have been out for years. But only as a single colour.

      The material in the article is capable of two colours, i.e. the news is the two colour part, not the colours themselves.

      --
      Carbon based humanoid in training.
    4. Re:And As Usual... by Red+Rocket · · Score: 1

      I think it was Max Planck who realized that the shorter the wavelength of the radiation, the more energy it takes to produce it. Combine that with the eye's reduced sensitivity to blue light (as compared to most other visible frequencies) and it follows that blue LEDs have to produce wicked-high photon energies to look comparable to their red and amber counterparts.
      Also, see this link.

      --
      - Hail to our fearless misleader! Fool speed ahead!
  4. Traffic by isorox · · Score: 2

    As long as they dont put them in traffic lights!

    1. Re:Traffic by Anonymous Coward · · Score: 0

      Why? Green and red are never on at the same time. Cities can economize by using one fewer bulb (or set of LEDs) in a traffic light.

    2. Re:Traffic by liquidice5 · · Score: 1

      I was about to go off about a dual color LED being more expensive than 2 single colored ones, but i went to Radioshack.com and realized that their R/G is 1.19, and the cheapest single color is .99, so, i didnt go off.

      But, what if the red burns out and the green is still good, (red is hotter or more energy or something)(i dont know which, but im sure they are different somehow), then u are screw, and im willing to bet that this new multi color EL material is more expensive then 2 single color EL's

      --

      Conscience is the inner voice that warns us somebody is looking - H.L. Mencken
    3. Re:Traffic by Bodero · · Score: 3, Insightful

      The colorblind can at least differentiate between red and green lights by the position of the illuminated light (top or bottom) the way it is now. If both were in the same spot, I can't say I'd feel more safe with the couple hundred dollars it may save the city.

    4. Re:Traffic by sjames · · Score: 2

      But, what if the red burns out and the green is still good,

      Can't happen, it's a single element that will either work or not.

      and im willing to bet that this new multi color EL material is more expensive then 2 single color EL's

      Without a doubt, it will be. However, they expect that the extra cost will be more than offset by the reduced physical complexity of the device. 1/3 fewer elements and traces = a better yield = cheaper. Another source of savings is that with 1/3 fewer traces to route, they can use more economical thicker traces (which will also improve the yield).

    5. Re:Traffic by Anonymous Coward · · Score: 0

      One could make them different shape (already done at some places), e.g. red: full light, green: forward arrow

  5. Yellow? by cdaley · · Score: 5, Interesting

    THey say they can make screens better by having only 2 elements per pixel, since this serves the function of two.....but if they have the same element making either red or green, depending on current direction, how do they make yellow, which is a combination of red and green light?

    1. Re:Yellow? by jman11 · · Score: 3, Insightful

      I'm no material scientist, but you could try putting an AC current through it at a rate that is higher than the eye could distinguish the two colours.

      Now, I'll add here that I am no expert on any of these things and this post is just me speaking through my arse.

    2. Re:Yellow? by tsa · · Score: 2

      I thought about that too, but what if the material is too slow to keep up? They must have solved this problem otherwise they wouldn't brag about this new material.

      --

      -- Cheers!

    3. Re:Yellow? by RedSirus · · Score: 1

      If the material is too slow to keep up, then we'd probably have problems using it in a screen at all. Very interesting question, though, and interesting solutions. I too, am speaking out of my arse, even in that limited first sentence of mine.

  6. Yeooouch! by bryanthompson · · Score: 0, Troll
    Philips does not expect to see the first application of the newly developed electroluminescent material complex until 2006 or 2007. That device will be a small polymer-based, full-color LED display -- "a few-inch screen" in a small appliance, perhaps something like a shaver, according to Hofstraat.

    At first when I read this, i couldn't help but think 'what the hell would you want a display on your razor for?', but then, realizing I was about to troll, i thought about the benefits...

    blade-wear indicator

    closeness of shave indicator

    battery power indicator

    It's just a matter of time before someone turns it into a webserver...

    1. Re:Yeooouch! by KieranElby · · Score: 1
      ... 'what the hell would you want a display on your razor for?' ...
      I bought a Braun 7570 with an LCD screen the other day; as you guessed it shows the power remaining + maintenance status. No closeness of shave control though (as far as I know!).
  7. Red AND green? by jwriney · · Score: 1

    Alright! EL Christmas lights can't be far behind.

    --riney