Solution based OLEDs - Page 15

Dupont announced new record lifetime performance in printed OLEDs for displays. They say that this is sufficient for OLED TVs. The new Gen 3 solution-processable OLEDs offer 29,000 hours for red, 110,000 for green and 34,000 for blue (at typical TV brightness levels). This is enough for 8 hours  per day over 15 years...

Back in 2009, Dupont reported even better lifetime for OLEDs. But these new materials can be used in a printing process, which should make it cheaper and easier to produce OLED TV displays. DuPont has produced some test devices with the new materials and will show them at SID.

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.

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.

Peptronics is an Israeli company, working on Polymer OLED materials. Their idea is to use a biological-based method to make the OLEDs. In the human body, we have 20 amino acids, used as building blocks for proteins. In the same way, they have made several "OLED building blocks", which can be used to create OLED materials, using Peptronics' peptide based technology.

Peptronics green OLED prototype

There are two types of OLEDs today: Small Molecules and Polymer based. Small Molecules are efficient and relatively easy to make, and are used in small displays today. But it is difficult to print them, and it is not easy to create a large panel using other methods. Polymer OLEDs are easily printable, and thus can be used to make large TVs - but their lifetime is short and they are less efficient.

Peptronics say that it will be possible to print cheap, large OLED TVs using their materials - which in fact will be printable (because they are polymer based), but also efficient - so it is the best of both worlds. The new materials can also be used for OLED lighting.

Peptronics are currently working on the finding the best "building-blocks" and creating numerous polymers from these building blocks using high throughput parallel synthesis. They then hope to sell their materials (or material-making systems).

The UK's printable electronics technology centre (or PETEC) has received a 20M GBP (about 32M$) investment from the UK's government and a regional fund (One North East). PETEC will double its facilities, hoping to begin a 15 billion GBP UK industry.

TOPLESS project OLED lamp prototype

PETEC is working on several projects, including OLED displays and lighting and solar panels. One of these project is TOPLESS, working on OLED lighting. PolyPhotonix, who are working on OLED light therapy, are opening a production line at PETEC.

Solterra Renewable Technologies (wholly owned subsidiary of Hague Corp) today announced an exclusive worldwide licensing agreement with the University of Arizona for the patented, intellectual property covering screen-printing techniques for OLED fabrication. Solterra's CEO Stephen Squires says that there are essential similarities between the screen-printing techniques to fabricate LEDs and the screen printing technology that Solterra is currently optimizing to print quantum dots to make thin-film solar cells.