Novaled - Page 9

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.

In addition to the innovative addressing concept and the new OLED MLA driver, a high temperature stable and long-living orange emitting PIN OLED layer stack was developed by Novaled AG. In automotive applications high reliability at 85°C
operational temperature and highly stable brightness (often only 20% reduction over lifetime is allowed) is required. The newly developed OLED stack offers an operating lifetime of currently 5.300 hours at 85°C and 20% brightness drop at an initial brightness of 600 cd/m².

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.

I recently had the chance to talk with the nice guys over the Fraunhofer IPMS in Germany, and the Institute Director (Prof Karl Leo) have agreed to do a short interview and talk about their OLED program.

These guys have been working on OLED since 2000, now organized under the name Center for Organic Materials and Electronics Devices Dresden (COMEDD). COMEDD's aim is to do not only research, but also pilot fabrication. More on COMEDD here.

Prof. Dr. Karl Leo, since 1993, is full professor of optoelectronics at the Technische Universität Dresden and starting 2007 institute director of the Fraunhofer IPMS. Additionally he is one of the founders of the Spin-Off Novaled AG.

Novaled announced that it has closed its third round of financing with a €8.5 million (or about $11.2 million) investment. Novaled will use the money to extend the commercialization of its OLED lighting and display technologies (PIN-OLED).

Novaled managed to raise this kind of money in a tough financial environment and it's good news for the company - which has been an OLED-Info sponsor since 2007...

Hodogaya Chemical and Novaled have agreed to offer hole transport materials (HTM) for Novaled PIN-OLED structures. Hodogaya has exclusively developed specific HTM for Novaled fitting very well with the Novaled PIN OLED structures. As a first result Novaled is enhancing its material offer with an additional hole transport material called NHT18.

The new NHT18 has a similar behavior in OLEDs like NPB, but provides additional advantages to OLED manufacturers. For example, the Tg of NHT18 is above 130C and thus gives a high temperature stability in OLED devices. The current efficiency in today's fluorescent blue emitting PIN OLEDs is 10% higher.

A research group of the Dresden Technical University (together with Novaled) has achieved record energy consumption for OLEDs. The achievement brings the organic LED technology closer to industrial volume production, and these OLEDs are prototyped at the Fraunhofer ITMS.

The research team achieved an efficiency of 26, 22 and 3.1 percent for red, green and blue organic LEDs which combined form a white light source. The low efficiency for blue results of physical differences — while red and green OLEDs are phosphorescent light sources, their blue counterpart is a fluorescent one, resulting in lower light emission. The difference, however, can be compensated for by increasing the active size of the blue light emitter as well as sending a higher current through it, explained research group member Rico Meerheim.