Novaled

Novaled and Plextronics will jointly develop doped and solution processed OLED materials. The two companies will develop an advanced solution processable Hole Injection Layer (HIL) technology for OLEDs. By leveraging Plextronics’ organic conductive ink technology and Novaled’s organic dopant technology, the companies will target these advanced HIL materials for use with solution processed polymer and small molecule emitters, as well as with vacuum deposited small molecule emitters.

Novaled and Plextronics aim to offer a solution processed HIL with the same performance as a Novaled doped small molecule HIL deposited in a vacuum process. They will co-market Plexcore OC inks that incorporate Novaled dopany materials.

Novaled announces a new 15x15 OLED device that has a 30lm/W power efficiency and 1,000 cd/m2 brightness. The OLED white light has a CIE color coordinates in line with the DOE energy star specifications. The lifetime is quoted as 20,000 hours.

The panel thickness is less than 2mm, and the light is a very high color rendering index (CRI) of 90. The perception of this light is similar to sunlight or what is delivered by incandescent bulbs. The achieved color coordinates of (0.44, 0.41) are inside the US Department of Energy (DoE) quadrangles at Illuminant A and even meet the more restrictive 7step MacAdams Ellispis around Illuminant A.

Novaled calls this new technology 'liternity OLED', which they want to start commercializing. It will allow upscaling to very large sizes.

The OLED100.eu project is a European 3-year OLED lighting project. The 30M$ project is a followup to the OLLA project, ended in June 2008, and it is lead by Philips, OSRAM, Siemens, Novaled and the Franhofer IPMS.

Dr. Stefan Grabowsky, the project's manager has been kind enough to talk to us, answer a few questions and give us more info on the project. Dr. Stefan has a Ph.D in Physics,  from the University of Duisburg. In 2000 he joined Philips Research labs. He's working on OLEDs for several years now, with a focus on device physics and OLED stack development. Since September 2008 he is the project manager for OLED100.eu.

Q: Stefan, thanks for taking the time to do this interview. Can you tell us a bit about OLED100.eu?
OLED100.eu is an European integrated research project that has brought together a consortium of experts from leading industry and academic organizations to accelerate the development of organic light-emitting diode (OLED) technologies. It has received €12.5 million funding from the European Community’s Seventh Framework Programme to form the technological basis for efficient OLED applications for the general lighting industry in Europe.

Large-area OLED from Philips

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.

The Fraunhofer IPMS Institute is working towards autostereoscopic 3D displays that use OLEDs as patterened backlight. They are showing a 3.5" 3D QVGA display, that uses a 80x60mm OLED backlight. 

The OLEDs are using Novaled's PIN-OLED tech, and are capable of either monochrome-green of full color.

Physicists from the Technical University of Dresden, together with Novaled has developed a new white OLEDs with efficiency of 90lm/w. They have used a new emission layer design and improved light outcoupling concepts. In fact, with special 3D outcoupling measures, they have achieved 124 lm/W.

Both values were determined in an integrating sphere with blocked substrate edges, only taking the light into account that is emitted to the forward hemisphere, CIE color coordinates are (0.41/0.49). An in depth article is published in today’s highly esteemed research journal ‘nature’.

“The potential of the devices is obvious when one considers that even at the very high brightness of 5,000 cd/m² a power efficiency of 74 lm/W is obtained,” comments Prof. Karl Leo, Director of the Institute of Applied Photophysics (IAPP, TU Dresden). “Thus high-intensity illuminations at very high efficiencies are possible as well”.

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.

Novaled has been showing a new OLED lamp prototype (they call it the "Victory Lamp"), at FineTech Japan. They have also been showing an OLED-wall, which is about one square meter in size, and made from 12 OLEDs (each 20x20 sqcm), and only 0.7mm thin.

We've got a short video and photo:

Novaled is showing their Defect Tolerant white OLEDs. Those displays maintain the appearance of a homogeneously lighted-up surface even in the case of electrical shorts, thanks to the use of its proprietary electrode design. One OLED element consists of two comb-shaped interlocked electrodes, which give a uniform light emission. If a short in one of the stripes appears, the resistance of the stripe will limit the current flow and prevent a further rise of current and temperature, which would otherwise destroy the OLED.

Novaled Ultra Stable OLED prototype

Novaled and Holst Centre have decided to collaborate under a joint development agreement. They will work on using the Holst centre's Organic TFT tech and Novaled's OLED dopants:

Novaled's doping technology contributes to very high power efficiencies and long lifetimes in OLEDs by improving charge carrier injection and transport in the organic layers. Novaled has shown that these effects are also relevant for organic TFT as the carrier injection from drain and source into the organic material has a major influence on the device performance. Novaled currently develops dopant and host materials which can be processed both in vacuum and in solution.

Read more in the original PR