MIT Develops Quantum-Dot OLEDs

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MIT Develops Quantum-Dot OLEDs

Posted by timothy on Monday January 20, 2003 @12:40AM from the cool-wallpaper dept.

deglr6328 writes "Researchers at MIT have developed a new type of Organic Light emitting Diode (OLED) using Cadmium Selenium Quantum Dots as the electron-hole recombination layer. It is widely believed that the next generation of flexible flat panel display technologies will be self luminous (non-backlit) organic light emitting diodes. However, the efficiency and lifespan of both small molecule and polymer type OLEDs, to date, has been poor for small wavelength emitting compounds. Using quantum dots as the emissive layer in OLEDs potentially solves both of these problems since they are inorganic and won't degrade, and they have a theoretical maximum quantum efficiency of near 100%. Mmmmm ... can't wait to buy my first roll-up display!"

22 of 158 comments (clear)

Cool... but when? by httpamphibio.us · 2003-01-20 00:48 · Score: 5, Insightful

Haven't roll-up displays been "two years away" for about seven years now?

I love the concept... but really, shouldn't we have at least one low quality, high priced, first generation consumer product by now?

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sig.
Amazing technology by gazbo · 2003-01-20 00:51 · Score: 5, Funny

Researchers at MIT have developed a new type of Organic Light emitting Diode
OLEDs potentially solves both of these problems since they are inorganic
Given this is quantum physics, perhaps this is an example of the uncertainty principle? Inquiring minds want to know...
1. Re:Amazing technology by deglr6328 · 2003-01-20 01:04 · Score: 4, Informative
  
  Sorry, I should have been more clear in my post I guess. The E-H (ie. light emitting) recombination layer will be inorganic CdSe quantum dots but the charge transport layers will be organic semiconductors.
  
  --
  - "Hear that?! The percolations are imminent! Cease your ingress!"
Re:Organic...... by theGreater · 2003-01-20 00:52 · Score: 5, Funny

I was curious as to which definition of organic this might entail...
* containing carbon
* back to nature
* obtained from living things
... but then it turned out I didn't care, as long as I get hi-resolution gaming. -theGreater.
Right now..already by hfastedge · 2003-01-20 00:53 · Score: 4, Informative

For some reasons the companies are just dumbass anal about it. They're have been flexible "e-paper" displays since 2000 as trials in federated department stores macys.

2 main companies currently lead the pack, BOTH have production facilities:

http://www.gyriconmedia.com/ Uses beads. berkeley->Xerox-parc->private. production fac. in michigan.

http://www.eink.com/ Uses organics but no where near as small as quantum dot-anything. MIT -> private. Manufacturing facility in Japan.

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Help my mini cause: My journal
1. Re:Right now..already by NoNeeeed · 2003-01-20 02:23 · Score: 5, Informative
  
  Which part of "self luminous" is causing you problems? Or did you not actually read the submission, let alone the article.
  
  The above links both point to "e-paper" type systems, which are monochrome, and require an external light source. These are great for a lot of applications, but I wouldn't want a laptop display built out of one.
  
  OLEDs and their ilk will produce their own light, and opperate with many colours at high speeds.
  
  Essentially it is horse-for-courses. E-ink is great for certain applications where power is critical (watches, cell-phones, even e-newspapers) and where update speeds are not critical (I beleive they are all 'mechanical' in some way), but OLEDs and similar will be necessary if you want full colour rapidly moving images. To equate the two technologies is to be somewhat disingenuous.
  
  A random googled OLED link.
  
  Paul
  
  --
  Paul Leader
Keep waiting by nesneros · 2003-01-20 01:03 · Score: 4, Insightful

I remember being a freshman in college, and making a dork of myself by telling all my friends how these things would be out in a year and how massively cool they would be. Oh, and electronic paper too. And those things had prototypes and everything. And even if they didn't, in 5 years or so a plasma display would only cost as much as a CRT.

Let's fast-forward 7 years to the present and there's an announcement that a lab has created a device, and we translate this to mean that functional products are just around the corner.

Excuse me for being such a cynic, but until something hits store shelves at an affordable price, its pretty pointless to get excited.

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Some men spend their entire lives trying to kill themselves for having been born. --Ross MacDonald
Short lifespan by BESTouff · 2003-01-20 01:04 · Score: 5, Insightful

However, the efficiency and lifespan of both small molecule and polymer type OLEDs, to date, has been poor for small wavelength emitting compounds
Apparently these displays would have a short lifespan. We would then have disposable screens. That seems a perfect consumer target: cheap, glowing, quickly obsolete.
1. Re:Short lifespan by Emperor+Shaddam+IV · 2003-01-20 01:25 · Score: 5, Insightful
  
  We would then have disposable screens
  
  With Cadium. Wonderful for the water supply and growing plants. My liver and kidneys can hardly wait. I could always use some more heavy metals in my diet.
mmm, high resolution by briancnorton · 2003-01-20 01:05 · Score: 4, Insightful

My roommates in grad school were working on this type of thing, and they were promising resolutions over 300 DPI. That makes me salivate, but I find it funny that for once display technology will be more advanced than image generation technology. (video cards) A 300 DPI, 17" widescreen would be a resolution of something like 4500x2500, or 11 million pixels, compared to 1 or 2 million pixels in a high-res display today. AGP 32X anyone?

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People who think they know everything really piss off those of us that actually do.
A step in the right direction but... by Drakula · 2003-01-20 01:13 · Score: 4, Insightful

using quantum dots does not solve the total efficiency problem. The overall efficiency of a LED is the product of the injection efficiency, the extraction efficiency, and the internal quantum efficiency. The inorganic quantum dots will make the internal quantum efficiency large, this is how well the device converts the injected electrons into light. However, the big stumbling block is the injection effeciency, how well the injected current is converted to electron-hole pairs for generating light. When this efficiency is low, a large amount of the applied power is lost to heat. This will need to be overcome as well before OLEDs of any type make as a commercial technology.

Also the cadmium selenide system is known to have lifetime issues. These, and related, materials were the first candidates for blue/green LEDs and lasers but suffered from horrible lifetimes.

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"It's comin' back around again..." -RATM
Cadmium? No thank you by freshwat · 2003-01-20 01:15 · Score: 4, Insightful

We're finally getting rid of extremely toxic cadmium in batteries and now this? Don't these guys learn? They have to engineer over the whole like cycle, including disposal.
For those miss the point by akincisor · 2003-01-20 01:18 · Score: 5, Insightful

The point of the article is that they have managed to use an inorganic layer in between just two organic layers and produce a magnitude of light equivalent to earlier efforts with 20 layers. These things have 25 times(!) the power efficiency. This might also be the first commercial application of quantum dots.
Huh by Morgahastu · 2003-01-20 01:27 · Score: 4, Funny

Researchers at MIT have developed a new type of Organic Light emitting Diode

...

since they are inorganic

This is like the episode of star trek where picard and some scientist debate if Data is a lifeform or not.
Re:roll up displays by Sycraft-fu · 2003-01-20 01:30 · Score: 4, Informative

Actually you'd probably be amazed how easy a good CRT is on the eyes. The problem is many people have cheap CRTs adn also often run their CRTs at 60Hz. A good CRT running at 85+Hz is really sharp, and at this point has superior colour to an LCD.
They use electricity, don't worry. by akincisor · 2003-01-20 01:34 · Score: 5, Informative

In normal LCD panels, the LCD itself just blocks light in strategic areas, and the image is formed by a light source that is behind the panel. This technology claims that the electricity will be passed through each pixel, which will produce the light necessary itself.
Never in Europe that's for sure. by jabuzz · 2003-01-20 01:37 · Score: 5, Informative

They are using cadmium, a nasty horrid posionous heavy metal that causes polution and soon to be banned from use in the European Union. Even lead in solder is to be banned shortly. Mercury another posionous heavy metal has already been banned.
1. Re:Never in Europe that's for sure. by farnsaw · 2003-01-20 03:08 · Score: 5, Interesting
  
  Common Research Cycle:
  First figure out how to do it with exotic materials that exhibit the behaviour you want, once you understand how this works, find more mundane (and less toxic) materials to create the consumer product.
  
  Many exotic materials have special behaviours that are great for research and creating devices that work in the lab environment but they often have drawbacks, not the least of which is their toxicity. These materials are also very expensive to produce, as well as dispose of, which will result in a consumer product that is too expensive for your average consumer.
  
  Manufacturers and consumers now look at the entire cost of a product from the initial manufacturing cost or purchase price, right through to the cost of disposing of it. Individual consumers usually don't pay much attention to the latter since they usually have one of an item (most /.ers excepted), however, corporations that often have thousands of each computer or display pay much more attention to things like lifespan and disposal costs. If this product is to come to market as more than a niche player, it needs to have a good ROI and low TCO.
  
  ROI = Return on Investment
  TCO = Total Cost of Ownership
  
  --
  "Computer Scientists can count to 1024 on their fingers" (non-mutant, non-mutilatated, human computer scientists)
Money answer? by swb · 2003-01-20 01:55 · Score: 4, Insightful

I wonder sometimes if "the powers that be" aren't just holding back on some of the new LCD-like display technologies because they've got a lot of money tied up in LCD technology that's just starting to show a return on investment.

And there's the whole recession thing, which has limited sales and maybe curtailed manufacturers' desire to invest in converting plants and equipment to make the new displays.

I know it seems a little conspiratorial, and the answer probably that the technology isn't reliable or mass producable yet, but I still can't help but wonder if the economy picks up we'll see from Apple or someone else not afraid to roll out an expensive 1st gen product and then see it approach commodity levels a couple of years later.

Although I keep asking myself why a 13" LCD TV sells for $800 and a 17" LCD monitor is $500. That's a market contrast I *don't* get, and the explanations I've been given about the cost of tuners and IR control logic don't add up, especially when a tube 20" is $170.
tell me when this is available by mrtroy · 2003-01-20 02:27 · Score: 5, Funny

I have several ideas with what I would like to do with this technology.
FIRST: make an invisible suit...you know the old deal with the cameras displaying the stuff on you so you look like your background or at least enough like it to blend in
SECOND: make an invisible *james bond* car
THIRD: make an invisible *harry potter* cloak
FOURTH: make my ceiling display some high quality pron for those kinky nights.
*Bows*

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[I can picture a world without war, without hate. I can picture us attacking that world, because they'd never expect it]
Re:In the dark about permanent illumination by dissy · 2003-01-20 02:37 · Score: 4, Informative

> I'm trying to get my head around the
> 'self-luminous' bit.

Your current VGA monitor is self-luminous.
You see the image because it is producing its own light.

LCDs are not, they *block* light from going through the display, and you see the light it does not block.
The light itself comes from a backlight, usually neon tubes that reflect off a reflective surface under the LCD panel itself.

Some LCDs simply have a mirror behind them and NO backlight (Think classic gameboy)
These work by having a mirror that external light goes in, bounces off, and hits your eye.. Only where the LCD isnt blocking light.

So these self-luminous displays will be monitor crisp/bright, better resolution, and flat.

Also, please dont confuse organic with alive.
The gas in your car is concidered organic, yet you dont need to feed it for power.
Next generation?! by ediron2 · 2003-01-20 03:50 · Score: 5, Funny

... the next generation of flexible flat panel display technologies ...

I realize I've been on a bender since New Year's Eve, but ... where was the first generation of these?

The only flexible flat panel I've ever seen was this palmpilot my friend sat down on, 'tho I really doubt it qualified as a display technology after he crushed it.