OLED ink jet printing: introduction and market status - Page 26

In February 2009, we interviewed Dr. Udo Heider, Merck's OLED Unit VP. Merck is a global pharmaceutical and chemical company based in Germany, working on high performance OLED materials. Dr. Heider was kind enough to do a follow-up interview with us...

Q: Dr. Heider, thanks for taking the time to do this second interview... Back in February you said that within nine months you'll have a solution-processable Green OLED ready. Any updates on that? What about Blue and Red?

Indeed it is with great pleasure for me to report that our development team has really done an excellent job in making progress and delivering results in the area of solution-processed OLED materials. Merck can now report that in a spin coating process, the gap between solution and evaporation processed phosphorescent green materials has been almost completely bridged. Merck is now shifting its focus to the implementation phase: this means working together with world renowned process and display manufacturers to make sure that these materials can now be printed in line with performance and yield requirements. We hope to report on results in this area in the near future. The extensive know-how that has been accumulated during the last couple of months in the areas of Green can now be transferred with confidence to the other primary colors Red and Blue. The key to success is based on combining the learnings and strengths of the Small molecule and Polymer OLED worlds.

CDT say they have produced an ITO-free PLED Lighting device, using a fine copper mesh. They have collaborated with Conductive Inkjet Technology (CIT) in the NOMAD project funded by the UK's government.

ITO is expensive and brittle, and is not so useful for flexible electronics. The new manufacturing method demonstrated in the NOMAD project reduces costs by eliminating ITO along with significantly reducing the capital and processing costs for patterning metal bus bars which distribute current and ensure the uniformity of light emission. CIT’s process eliminates the need for traditional vacuum sputtering equipment and etching tanks.

The Holst Centre has released a new proprietary roll-to-roll (R2R) sintering platform for fast and low-temperature curing of printed conductive structures. The center is progressing towards a complete tool set for R2R manufacturing and can be used for plastic electronics such as flexible OLEDs, organic PV solar cells and more. Holst' line now includes printing, coating, drying and lamination stages in addition to the new sintering unit. A vacuum deposition stage is currently in development.

Screen printed structures on foil photo

High web speeds and low temperatures are key elements for R2R manufacturing of plastic electronics. The sintering platform uses a new photonic sintering process, developed by Holst Centre, which heats only the printed target material rather than the whole carrier substrate. The tool can sinter printed conductive structures in less than a second, which is already enabling a fast throughput speed of over 5 meters/minute. It also works at significantly lower temperatures than traditional sintering techniques, preventing distortion of the carrier substrates and reducing energy costs.

Back in September we reported about Kateeva, a new startup that developed a method for printing OLEDs. Now we hear that the company is testing a prototype printer that can print displays sized 1.8x1.5 meters. Kateeva's CEO says that they are in talks with 'leading display makers' to test the printer and inks in 2011.

Earlier today we got word that Pioneer and Mitsubishi Chemical will jointly develop OLED Lighting. Now we have some more information. Pioneer will be the one to actually make the panels, and Mitsubishi will sell them across Verbatim's worldwide sales network. The plan is to start mass production in 2011, with a sales target of $335 million in 2015 and $1.1 billion in 2020.

The two companies are currently researching OLED lighting panels that use printable hole injecting material (HIM) and new emitting materials, and will also research printable OLED lighting development and commercialization. Mitsubishi plans to start early stage mass production and marketing of new printable emitting materials, which are probably the PHOLED materials developed together with UDC.

We'll be able to view their first prototype (a dimmable/tone adjustable OLED panel, which Mitsubishi say it's the world's first) at the Light+Building exhibition, April 11-16 Frankfurt, Germany.

The Flexible Display Center (FDC) at Arizona State University today announced that the UK's PETEC (Printable Electronics Technology Center) has become an Associate Member to collaborate on high-performing organic thin film transistors (OTFTs) for flexible display applications. OTFTs has potential in all sorts of display technologies such as e-paper and OLEDs.

The FDC is also working with UDC on flexible OLEDs. Earlier in 2009, they have already demonstrated a 4.1" monochrome QVGA PHOLED display.

PETEC was opened in March 2009. One of the companies that are building a production line is PolyPhotonix, who are working on OLED lighting.

It seems that Sony are very serious about printed flexible OLEDs. In June 2009, they have created a group whose goal is to launch the flexible OLED panel business "as soon as possible". They had several researchers working on organic TFT in several departments in Sony, and now they all work in the same group.

Sony Flexible OLED Prototype (CES 2009)

Sony wants to 'change the fundamental design of equipment" using the new flexible displays. They have already shown us flexible-OLED prototypes (photo above, and video below). Hopefully we'll hear more at CES 2010 next week.

Casio Computer wand Toppan Printing will form a new joint-venture to develop and produce OLED displays. The new JV, which will begin in February next year, will combine Casio's display production technology with Toppan Printing fabrication technology.

Casio will set up the firm with around 600 employees (from Casio's OLED development team and LCD production unit), and will later sell a 80% stake in the firm to Toppan Printing.

GE is working since 2003 on roll-to-roll OLED printing (of flexible and transparent OLED lighting panels). Dr Yan from GE says that in 2007, they had fairly high defects, around 65% yield. Today GE says that their yield is between 90%-95%.

One of the biggest issues GE is tackling is the flexible barrier layer to protect the OLED devices. GE has developed an "Ultra High Barrier" (UHB) by plasma enhanced chemical vapor deposition. The performance that has been achieved is low 10-5g/m2/day, with good transparency and adhesion.

Dr Yan says that roll-to-roll organic printing is real, and OLED lighting is getting closer. OLEDs are still around 15 times more expansive than conventional lighting, but the price will drop in time, and OLEDs will get cheaper than LEDs because of roll-to-roll printing and potentially cheaper materials.

IDTechEx believes that it will take between 5 to 10 years for OLEDs to become cost effective. But even before that OLEDs can be used in high-value products and niches.

Kateeva is a new startup, that has developed a new way to deposit OLEDs - using an inkjet printer and a micro-dryer called a T Jet (thermal Jet) along with proprietary inks. This will allow makers to use Gen 8.5 and larger substrates to make OLEDs.

Kateeva say that in four years (or more...) OLED TVs made using Kateeva's way will cost around 70% of what it costs to make a standard LCD.

Kateeva's T Jet sits between the inkjet nozzles and the substrate. The material is first heated to 100 Celsius to evaporate the carrier liquids. The remaining solids then get heated to 300 Celsius, turned into a gas, and deposited onto the substrate, where it solidifies.