The final symposium of the OLLA OLED lighting project took place on the High Tech Campus in Eindhoven Netherlands 12.6.08 with about 80 attending the exhibition and about 60 attending the half day conference. The objective is to start the work that will lead to replacement of many of the "6 billion lights that the world buys every year". Presentations from OLLA, Siemens, Novaled, Fraunhofer IPMS, Philips Lighting OLED Development and Royal Philips Electronics and the exhibition alongside revealed that the objectives had been met or exceeded. These objectives embraced laboratory demonstration of sharply improved life for 1000 cd/m2 emission and larger panel size etc, compared to what was available when the project was conceived five years ago.
Polymer OLEDs, despite being printable, were bypassed early on to concentrate on glass sandwiches of small molecule OLEDs. Here, phosphorescent layers exhibited poor life so hybrid variants of the long life Novaled PIN OLED construction was favoured. All this had echoes of Philips earlier abandoning P-OLEDs on the same campus.
This sits in some contrast with Sumitomo of Japan, which was present. Sumitomo bought leading P-OLED company CDT of the UK, which has the largest number of key patents in the subject, and it has now decided to enter the TV display business with this technology with very large investment. Needless to say, this will require very long life OLEDs without compromise on colour, which is a huge challenge for the industry at present. An alternative approach is to make products that do not need long life. Indeed, UK startup Polymertronics has just raised $9 million to make P-OLED billboards and posters and Add-Vision in the USA is another company commercialising the technology, in this case for smaller devices. The contrast with OLLA majoring on small molecule OLEDs is partly explained by the fact that this project was pre-competitive research looking for best performance not best marketability, flexibility, price or other criterion.
An interesting aspect revealed in discussions was the fact that the distinction beteeen small and large molecule options is breaking down with printing small molecule precursors that are cured into small molecules and, more recently, focus on slightly larger small molecule oligomers that cannot be sublimated but can be printed. Some side chains can also help in this respect. However, the effect of even minor changes of molecule on electrical, optical and rheological properties is highly complex and not fully understood.
IDTechEx asked many of those present how the traditional glass structures made by OLLA compare with the US and East Asian competition - including the flexible OLED lighting demonstrated by GE as a reel to reel process. No one could comment, other than to say that test standards are not agreed for meaningful comparisons to be made. There is no OLED test organisation in the world comparable to National Renewable Energy Laboratory NREL in the USA that is the internationally recognised referee of claims for excellence in photovoltaics because it replicates experiments under standard conditions. This will be addressed, possible candidates including the Physikalisch-Technische Bundesansalt of Germany and various Fraunhofer Institutes in Germany, all of which were represented at the event.
With the Konarka Minolta joint venture with GE promising to commercialise OLED lighting in the USA within 3 years and many Japanese gearing up for production of OLED lighting on their own, such as the Lumiotec, a joint venture involving Mitsubishi and Toppan Printing aiming to sell OLED lighting next year (read our article about Lumiotec here), it would be nice to see some robust plans for major commercialisation of OLED lighting in Europe, where the academic base is excellent and there are several putative material suppliers with well funded operations and excellent technology. Certainly Osram and Philips have huge lighting businesses to defend and they are well aware of the opportunity and investing in development.
Smaller groupings of participants than those in OLLA are now progressing OLEDs in other EC programs such as CombOLED and some of this work was also described at the event. Meanwhile, the OLLA participants see a progression from OLEDs being used for art works to the first major application being signage. OLLA found that copper patterning is essential for wide area OLEDs, in order to distribute potential evenly.