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OLEDs May Generate Electricity

Posted by timothy on from the another-step-toward-off-grid-computing dept.

NewmansDaddy writes: "According to a PCMag article, 'When the OLEDs are working as a display, you apply electricity to the materials and they emit light. It turns out, however, that if you apply light to these devices, you can get them to produce electricity; in other words, they will run backward...'"

21 of 43 comments (clear)

  1. Renewable lighting? by darylp · · Score: 3, Interesting

    How well do these work when compared to traditional Solar Cell based components? With the addition of a few capacitors, it would be nice to have OLED lighting which would recharge during the day.

    1. Re:Renewable lighting? by Astrorunner · · Score: 2, Informative

      A OLED working as a light is a different animal than an OLED working as a solar cell, so, you can't have your cake and recharge it too.

  2. finally by tps12 · · Score: 3, Funny

    The solar-powered flashlight is finally a reality.

    --

    Karma: Good (despite my invention of the Karma: sig)
  3. So??? by ka9dgx · · Score: 4, Informative
    LEDs are also photoelectric. I built a sensor with two of them, one as a photodiode. I did this 8 years ago, for fun while visiting my friend in Florida.

    --Mike--

  4. OLED's have signifigantly shorter lifespans by Hadlock · · Score: 4, Interesting

    LED's have supposedly 100,000 hours of use in them. of course, that's at about half intensity, and they still dim over time, and it's not been fully proved (LED's haven't been mainstream for 10 years really)....

    OLED's supposedly have somthing like a maximum of 30,000 hours of life.... would using them as primitive "solar cells" decrease their lifespan considerably? or is this a possible reason as to why they have such a short lifespan?

    on a somewhat completely unrelated topic, if increasing battery life is so damn important, why haven't they started including $3 radio shack 3v solar panels on everything in existance? or does the voltage/amperage have to be >= standard voltage of the battery? we have a 200mA trickle charger for our 12v deep cycle boat battery...

    would i be able to run/charge my m100 off a $3 3v solar cell? if i underclocked it? yes, i realize it's usually in my pocket....but it does sit underneath a hallogen light when i'm @ the computer...

    --
    moox. for a new generation.
    1. Re:OLED's have signifigantly shorter lifespans by Yarn · · Score: 3, Informative

      Lifetime is longer for solar cells as the electric fields are lower.

      I doubt that a $3 solar cell would provide enough current to run a palmtop. Find the wattage requirements, solar cells are approx £10 per watt.

      --
      -Yarn - Rio Karma: Excellent
    2. Re:OLED's have signifigantly shorter lifespans by Elazro · · Score: 2, Interesting
      Re: Solar cells on portable electronics.

      They are starting to do this - an acquantaince of mine has a cell-phone with a small solar panel, which is indeed a trickle charger for the phone's battery. You can still charge it in a standard charger, but it does prolong the life of the battery. Apparently, these things are all the rage in California.

      I'm not sure where he got his from, but I've seen them for sale at www.snpower.com. Only cell-phones, and I have no experience dealing with that particular company. -matt

    3. Re:OLED's have signifigantly shorter lifespans by Artifex · · Score: 2

      LED's haven't been mainstream for 10 years really

      What?!? I was buying LEDs from Radio Shack about 20 years ago, when I was discovering "neat stuff" - I think a pack of 15 or 20 assorted LEDs was around $2.25 back then... (I'm sure my dad knew better than to ask why a 10 year old was wasting his allowance on stuff like that, because he probably bought vacuum tubes as a kid)

      --
      Get off my launchpad!
  5. Ah, photonics by Yarn · · Score: 5, Informative

    A friend of mine has been working on organic solar cells for the last 4 months (MSc Project), he's hoping to reach 4% efficiency. Last time I spoke to him he was just about to put the ITO transparent contacts on, then test it with different wavelengths of light.

    The possibilities of making organic solar cells have been considered almost as long as organic LEDs have been known (one of my professors was in the Cambridge group who discovered the effect) but the efficiency will probably never be near that of good polycrystaline silica.

    To power my laptop I'd need half a metre square of high grade solar cell, about £500...

    --
    -Yarn - Rio Karma: Excellent
  6. not both by bearbones · · Score: 3, Insightful

    Read the article

    It says that to generate electricity it needs to be formulated differently.

    So you get a display or a solar cell, not both.

    But, maybe they can work on an new proccess that does both.

  7. Remind anyone else of... by Zarquon · · Score: 3, Informative

    Douglas-Martin sunscreen's from Heinlein's stories?
    IIRC, their functionality was based upon the firefly's light reaction.

    --
    "'Tis great confidence in a friend to tell him your faults, greater to tell him his." --Poor Richard's Almanac
    1. Re:Remind anyone else of... by Zarquon · · Score: 2

      They said 'Give it away' but they meant 'License it for a small royalty'.. $.02/sq. ft. or some such. But it did go from Trade Secret to Cheap Patent because of the Mob and Moneyed Interests. And there was the obligatory reference to secret, high-milage car. Good short, have to dig it up again. But yeah.. it was high, once they removed the visible light filters. And 'made from common clay' or something.

      --
      "'Tis great confidence in a friend to tell him your faults, greater to tell him his." --Poor Richard's Almanac
  8. Fun with LEDs, not just OLEDs by JUSTONEMORELATTE · · Score: 3, Informative

    Take a yellow or green LED and shine your handy-dandy green laser pointer ($150 @ thinkgeek, support your sponsors!) directly into the lens. You get a little over 1VDC output from the LED, but only a few milliamps of current.
    I learned this trick from this page at the LED Museum. Theres a picture of this stunt there as well.

    This story seems newsworthy because it's nifty new OLED properties, but it's not really news that you can get an LED to rectify some electrons out of a light source.

  9. Bah humbug by BoBaBrain · · Score: 3, Insightful

    In the same way that a speaker will work as a microphone?

    Just because it's possible doesn't make it a good idea or even news...

    --
    I am a Karma Library.
  10. Bad Consequences? by SanLouBlues · · Score: 3, Insightful

    Hopefully they don't work too well. Otherwise a flash photograph could fry the display chip on OLED using pdas. I guess they might need to start surge supressing the display.

  11. photoelectric LEDs by ka9dgx · · Score: 4, Informative
    LEDs are clearly PhotoElectric. They do generate measureable (but only slightly useful) amounts of current in response to incident light.

    They are also spectrum sensitive, picking up only equal or higher energy photos. This can be verified with a microAmp meter, and a set of various high-brightness LEDs. You'll observe that a red LED will pick up red or shorter wavelengths, green only detects green and shorter wavelengths, etc.

    (Red has the longest wavelength (and smallest energy per photon) of visible light, violet is the shortest wavelength, and highest energy photon.) The high energy of blue is why it's been so hard to make a blue LED for years.

    Put them face to face, run the source LED at its rated current, and expect a few microAmps out of the other LED..

    --Mike--

    1. Re:photoelectric LEDs by Gordonjcp · · Score: 2

      I've just checked it with a small green LED and my plain ordinary digital multimeter, and sure enough, there's a tiny current there. The meter is quite high impedance, doesn't have a current scale, so what you're seeing is the voltage drop across a high resistance.
      Anyway:
      Dark: .27mV
      Light: 23mV
      This is on a fairly overcast evening, still a bit sunny though. Not particularly bright outside.

      So what happens if you join a hundred or so LEDs in series? If you shone a light on 99 of them, would the hundredth light?

  12. nope by bcboy · · Score: 2, Insightful

    Efficiency is only part of the issue. The other is expense and difficulty of manufacturing. If it's less efficient but cheaper, it's still viable.

    1. Re:nope by Peter+T+Ermit · · Score: 2, Insightful

      Even with 15% efficiency solar cells, you probably wouldn't be able to power a laptop or extend its battery life appreciably. The point I was trying to make was that even if this stuff were cheap, and did last, and were easy to bond with computer cases (none of which is obvious), it would still be useless because of this.

  13. Question... by bmh5c · · Score: 2, Interesting

    Does anybody know how expensive OLEDs are? If they can be sprayed on using inkjet printing procedures, could I just paint my whole house (or at least my roof) with them? Probably wouldn't power much, but it couldn't hurt...

  14. Well Duh! by zenyu · · Score: 2


    LED's will too, it's just a Diode. Just like Solar Cells. They are made differently though cuz the solar cell needs to have a large surface area to be efficient, the [O]LED is designed as an emitter, it doesn't. (They also use different materials for different bandgaps & hence color.)