Lifetime

Universal Display and Seiko Epson have been working on their inkjet printable, phosphorescent OLED technology and materials for quite some time... They have now announced new advances in performace:

• A red P²OLED with CIE (0.67, 0.33), an efficiency of 10 candela per ampere (cd/A) and an operating lifetime of 20,000 hours, to 50% of initial luminance of 1,000 nits
• A green P²OLED with CIE (0.33, 0.62), an efficiency of 34 cd/A and an operating lifetime of 25,000 hours.

Last month Seiko Epson has unveiled a new inkjet-printing technology for OLEDs, suitable for large sized panels. We have talked to Satoru Miyashita, General Manager of Seiko Epson's Core Technology Development Center about this new technology and their plans for OLED production.

Q: You have shown a new ink-jet based OLED technology. You say it will enable 37" or larger HD-OLED TVs. Do you have any plans to actually make such TVs? When do you think products can be made with this new tech?
Epson is currently considering a variety of options regarding the commercialization of this technology, but at this point no specific announcements have been made about plans. We see 2012 as being the year that 37"+ OLED TVs will be launched by various makers, and 2015 as the year that sales will really take off for this market.

Espon 14-inch Inkjet processed OLED

Novaled and Kodak have developed  anew white PIN OLED, to be used in RGBW displays. The display is based on Novaled's p-type and n-type doped transprot layers and Kodak's emitter systems. The companies showed two devices - single unit and tandem-white OLEDs. 

For the single unit devices, 15.8-cd/A with a lifetime of 30,000 hours and color coordinates of 0.32/0.35 at 1,000 candelas per square meter were reached. In the tandem device approach a current efficiency of 33.2 cd/A at color coordinates 0.28/0.31 was achieved. The lifetime of the device was 77,000 hours compared to 51,000 hours that were reached with devices based on conventional Li-doping for the connector unit

In a display simulation the tandem device compares favorably with a conventional tandem device based on Li-doped p-n connectors; allowing display lifetime to be improved from 38,000 to 53,000 hours.

Universal Display and Samsung Mobile Displays present advances in green Phosphorescent OLEDs at SID. This new material will be used in both hand-held devices and OLED TVs, extending lifetime and efficiency. UDC's red materials are already used in Samsung's AMOLED displays, and it's likely that we'll see Samsung use their green materials as well.

The companies showed a highly-efficient, green UniversalPHOLED material that has been used in a top-emission PHOLED device architecture. Using this approach, they achieved two milestones. A green PHOLED with NTSC color at CIE(0.20, 0.73), high luminous efficiency of 110 candelas per Ampere (cd/A), and a low voltage of 3.6 V at 3,000 candelas per square meter (cd/m2) was achieved.

A second device structure using this green PHOLED material system also achieved an ultra-high luminous efficiency of 160 cd/A along with CIE(0.28, 0.69) and low voltage of 3.8 V at 3,000 cd/m2. These compare to a standard bottom-emission device with CIE(0.33, 0.62) and 52 cd/A using this same green PHOLED material system. Replacing the green fluorescent OLED material typically used today in an AMOLED with this new green PHOLED can result in a significant 37% power savings.

Toshiba Mobile Displays (TMD) shows a new 4.15" AMOLED display. The panel has a 60,000 hours at 200cd/M2. The display uses small molecule OLEDs with a top-emission structure. There's no word when such panels will be available...

We also hoped to hear more of TMDisplay's OLED TV program (TMDisplay are working towards HDTVs together with Panasonic), but I guess we'll have to wait some more...

A few years ago, lifetime was the biggest issue with OLEDs, but it seems companies are showing very rapid advances. Dupont announced today that they developed new (third Generation) printable, solution process OLED materials.

The Green Gen3 material has over one million hours lifetime (that's over 100 years of constant use!) with 25 cd/A efficiency. The color coordinates are 0.26, 0.65. 

The light-blue Gen 3 (color coordinates 0.14, 0.12) has 38,000 hours from 1000 cd/m2, efficiency of 6.0 cd/A, and a lifetime of 38,000 hours. A deeper blue (color coordinates 0.14, 0.08) was developed with 7,000 hours. Due to its deep blue color, the lifetime of this material at the luminance required for a 200 cd/m2 display is calculated to be approximately 41,000 hours. 

The Gen-3 red has a lifetime of 62,000 hours, current efficiency of 13 cd/A, and color coordinates (0.68, 0.32). 

Novaled, Fraunhofer IPMS and Optrex Europe developed a new, unique PMOLED driver. They have implemented an innovative MLA scheme called SELA (Summed Equiline Addressing). Basically, instead of driving using a single-line addressing scheme, the SELA allows parallel driving of multiple rows, thus preventing high current amplitudes.

Basically this means that we get higher lifetime, better resolution and better efficiency in the OLED display. The driver is specified for operations between -40°C and +125°C, exhibits an OLED drive voltage up to 25 V, and a column source current up to 2 mA. In particular the latter can currently not be fulfilled by any commercial available PM OLED driver.

We've got some more info on LG's 15" OLED, shown at CES. The screen is 1.4mm thick, and expected to go into production in June. The resolution is 1366x768, and the reported lifetime is 30,000 hours.

LG 15" AMOLED at CES 2009

LG will not release this as a 'luxury' item (like Sony's XEL-1, priced at 2500$). They are waiting for customers to put this in laptops, and only then will they begin producing the displays.

Check out 2 more photos of this great looking TV:

Several companies are giving updates on OLEDs in CES.

• CDT are demonstrating near-eye viewer with P-OLEDs. CDT also shows screen-printed flexible OLEDs together with Add-Vision.
• Idemitsu Kosan shows both fluorescent and phosphoscent based OLEDs, with long lifetime. They are also showing white OLEDs for lighting.
• Ignis Innovations areshowing a prototype 2.2" QVGA OLED with their backplane and driver tech, amied at reducing cost and improving manufacturability. 
• Novaled shows a defect-tolerant OLED light source. Novaled's demonstration delivers more than three times the efficiency of standard incandescent light bulbs and lasts ten times longer and has no Mercury.

Plextronics announced today that its conductive ink has been shown to improve the performance of certain P-OLED devices.