I can’t think of a display technology that has generated more interest than OLEDs since the advent of LCDs. Any shred of news gets bounced around the Web like a ball of flubber in an instant. So while there was some OLED news at SID 2011, some of the most interesting details were the ones that weren’t said.
Among the points that were made were new lifetime specs for OLED materials from Universal Display Corporation (UDC). The company now rates its green-yellow phosphorescent material at a mere 1.4 million hours to half brightness. They also have a red that they rate at 900,000 hours. Blues remain the limiting factor; their light blue has improved to 20,000 hours to half brightness, but that’s still a lot lower than the other colors.
UDC also announced a new encapsulation technology. The single layer is a homogeneous mixture of organic and inorganic materials, which is far simpler than the complex multi-layer approaches that alternate organic and inorganic layers in a many-layered stack. UDC’s new material is compatible with roll-to-roll fabrication, which would make it useful for manufacturing flexible displays.
Perhaps the more interesting details were the ones that were not made, however. The biggest dogs that didn’t bark were Samsung and LG, who didn’t show OLED panels this year. The word on the street was that it is normal for companies like this to “go dark” prior to making commercial announcements. Since we expect to hear news of large format OLED panels — suitable for TV use — by the end of this year, their silence makes sense.
There was another interesting missing detail for those who were watching. In a presentation, a DisplaySearch analyst showed a slide listing polysilicon production lines, either in use now or on the drawing boards. Another slide listed OLED fabrication lines. LG’s Gen 8 OLED line was listed to start production early next year, but there was no corresponding polysilicon line listed that can handle substrates that large. The reason for the missing substrate line is that LG won’t be using polysilicon for the active backplane for their OLED panels. Instead, they will use new metal oxide technology that should be easier to create on large substrates. This move has actually been made public already, but it could be easy to overlook.
The interesting part is that Sharp is converting about one quarter of its Kameyama 2 Gen 8 amorphous silicon line for LCDs to metal oxides. Not only does this mean that the technology could improve performance for LCD panels, OLED panels could finally use the same substrate technology as LCDs. This could help accelerate the cuts in manufacturing costs which could make a big difference in whether or not OLED will be able to compete.
So it looks as though we may have to show some patience before we can cite some major breakthroughs for OLED displays, but it looks as though we should hear some interesting news before the year is over.