Have scientists captured the gold ring for blue OLED?
A thorny barrier to development of low-cost, high-use OLED displays may be out of the way at last, if reports from South Korea pan out.
OLED (organic light-emitting diode) systems promise crisp displays, lovely illumination, truer blacks, wider production-tech options, thinner materials, faster refresh rates, world peace, six-pack abs, and smarter power consumption all around. The problem is that the technology requires lights in all three primary colors of the additive-color model (red, green, and blue), and moreover requires them to last roughly the same amount of time whatever color they are. Though scientists have long since unlocked the secrets to cheap, long-lasting green and red lights, blue has been elusive.
That's not too confusing if you think about the electromagnetic spectrum, blue's comparatively short wavelength, and how an OLED works (PDF available here). OLED colors are generated when current passes through fluorescent material. It takes more juice to get blue pixels excited enough to fluoresce -- which means they burn out (well, fade) much more quickly, with lifespans half or less than that of their green and red cohorts.
|One of DuPont's current "solution-processed" OLED displays. Notice how in this and several other demonstrations, very rich red and green colors are featured, but rarely blue.|
The differences aren't enough to greatly affect small-scale OLED usage -- the screen in your mobile phone, for instance, isn't viewed often and continuously enough to make much difference -- but it's seriously holding up production on the paper-thin monitors and ginormous flat TV sets that cause so much excitement when OLEDs are discussed. It has been theorized that a more efficiently excited material would lead to a better, cheaper, long-lasting blue, and that's what the Korean team says they've found.
So far, little information on the advance by Pusan National University scientists has been made available. The team, led by chemistry professor Jin Sung-Ho, is composed of both university researchers and engineers from Seoul National University, and is state-funded. South Korea is currently the world's largest producer of LCDs (liquid-crystal displays) and competes bitterly with Japan in the newer OLED field.