In June 2008, I had the chance of interviewing Dr. Geoff Williams, Topless's project manager. Geoff has a PhD from University of Durham, and later worked in Philips Displays and he now works in Thorn lighting.

Project Topless (Thin Organic Polymeric Light Emitting Semi-conductor Surfaces) is a three year £3.3M project sponsored by the UK government to 50%. It comprises a consortium of Thorn Lighting (UK largest lighting company), Sumation UK and the University of Durham (Department of Physics and Chemistry). The aim of the project is to product a high quality white light generating single polymer, and efficient large area single pixel device architectures.

The challenges are:
  1. An efficacy of 20lm per watt
  2. Colour temperature suitable for general white light applications (this varies according to customer requirements) between 2,700K to 17,000K.
  3. Large single pixel devices (no buzz bars)
  4. Minimal number of organic layers
The project begun in March 2007 and will run to Feb 2010.
Q: Hello Geoff, thanks for agreeing to do this interview. What are the goals of the TopLess project? What will you consider to be a big success in the project?

Project Topless's mandate is to develop high quality stable white light emitting long lifetime polymers, and design device architectures which are optimised for efficacy and simplicity of manufacture. To this end I believe a 'big' success would be to challenge existing in-efficient fluorescent systems on colour rendition, life and efficacy.

Q: You are working on a "large single pixel devices". What do you mean by "large"?

The largest single pixel systems Topless is capable of producing is 25cm2, limited by size of cathode evaporator. However, the knowledge gained as part of this process is transferable to much bigger pixels, 400cm2. My definition of single pixel is a continuous emissive surface without buzz bars.

Q: You want to achieve a minimal number of organic layers. Can you elaborate on that?

Not wishing to fully elaborate on how we are aiming to achieve simple architectures, the purpose is to produce a device which is simple to make. The opportunity to realise repeatable simple manufacturing processes can only come from minimal numbers of manufacturing operations.

Q: We are aware of two other european lighting projects - OLLA and Fast2Light. Are you collaborating with those projects?

I am aware of OLLA and most recently Fast2Light. I am now collaborating with neither of these projects, but I do wish them success in their expectations and aims. I did, however, study in the University of Durham with Mary Kilitziraki, and will take the opportunity to establish communications once again.

Q: You are focusing on Polymer-OLEDs (PLEDs), CDT is obviously the major player here. What are the advantages of P-OLEDs over 'regular' OLEDs?

As far as I am concern there are many advantages, although the technology still lags behind OLED systems in terms of efficiency and predict life, although this gap is closing. The distinct advantages of P-oled will manifest themselves in volume controlled manufacturing. With the tremendous support of the chemists and physicists in Sumation and University of Durham, complex polymers and optimised device architectures are beginning to emerge. Thorn's aim is to translate into manufacturing the knowledge gained in the research laboratory.

Q: I understood that OLLA gave up on P-OLEDs, and decided to use SM-OLEDs instead, as did Philips. I wonder what is your thoughts on this?

The conversations I've had with Philips is they needed to make a decision on the way forward for OLLA in 2004, then OLED was by far superior to p-oled in many respects and although they accpeted the complexity of device assembly was always in favour of p-oleds they took the advanced performance decision.
They may have taken a different one today, but who knows.

Q: What exactly are the roles of Thorn, Sumation add Durham University in the project?

Thorn is the route to the general white light commercial market place, globally. We are the UK's largest commercial lighting supplier. Working in conjunction with customers and understanding their requirements is essential to shorten the time to market. It is the expectation of Topless that the next stage is to create a manufacturing capability suitable to make the R&D leap into manufacturing.

Sumation brings several decades of p-oled knowledge, principally gained in materials suitable for the display market, however Topless gives them the opportunity to have a concentrated effort in producing quality single white light emitting materials, usable in displays and lighting. They have a combination of physicists and chemists working on this project.

The University of Durham, Physics and Chemistry, bring an established inter-departmental collaboration capable of creating, evaluating and device testing new polymer materials. They have the ability, within their photo-physics group to understand precise charge transfer within the polymers, this is a valuable to feedback tool for the development of the next generation of materials, either in Durham or Sumation.

Q: Will you consider using printing to lower the cost of manufacturing?

It is important to rule nothing in or nothing out; what is important, however, are the processes which will deliver the best yield and therefore material utilisation, control and product cost.

Q: There are many companies and projects researching OLED lighting. Who do you think are leading in this race?

The field of OLED lighting is complex, what is meant by lighting? general, architectural, indicator etc. The lighting market place is huge and diverse, no one company will dominate the European market never mind the global market. Those companies which listen and engage with their customers and suppliers will be successful.

Q: Recently OSRAM showed the world's first OLED 'lamp' in a beautiful design. Can you comment on this?

Osram's product is appealing and demonstrates the new opportunities designers have with this thin film technology. As the technology embraces conformal or flexible substrates much greater and diverse design features will become available.

Q: One of your goals is to achieve an efficacy of 20Lm per watt. We hear that some companies already claim to reach those values - in fact UDC presented a 'warm-white' OLED with 30 lumens per watt. Can you comment on that?

Efficiency is certainly important and I expect Topless will achieve 20lmW or even better, but I need to evaluate the bigger picture; there are many parameters which will determine P-oled technology success, efficiency is one, and one which can not be ignored. However, in parallel with improving all the parameters will allow greater market opportunity.

Q: Konica Minolta is another competitor. They are working with GE and UDC, and plan to launch OLED-lighting products in 2011. Do you think this is realistic?

Yes, this is a realistic timescale, but once again success isn't just making a statement. Have they or are they developing the market with identified product they are confident they can make in volume?

Q: Another new white-light 'competitor' is Lumiotec, a new Japanese JV announced in May. What can you tell us about their efforts?

I have only recently come across this business and from what I understand their aim is to evaluate the market opportunities through product sampling and exploit sectors suitable for present day product capability. This is an exciting venture, and one which I most certainly will be watching with interest.

Q: Who do you see as the future leader in OLED lighting? Europe, the US or Japan?

P-oled manufacturing will not be labour intensive, the price of raw materials are no cheaper in the far east or US, there is no obvious benefit for a European, US or Japanese product to locate their manufacturing other than in their region. Lighting is very particular and varies regionally, understanding and knowing your market is important, speed to market and customer after-sales commitment can not be ignored, therefore I believe no one region will dominate.

Q: One of the nice things about OLED lightings is the ability to create radical new designs. Will you be working on applications too? Do you plan to work on flexible or transparent OLEDs?

This is a tremendous opportunity to think out of the 'box' whilst maintaining product performance which complies with the international lighting standards. Why replicate what exists? To this end involving aesthetic designers is imperative, allow the imagination to run wild!

There is no evidence at this stage to suggest flexible is the customer's choice. There are technical issues which also need to be overcome, such as the moisture barrier layer problem, and mechanical integrity of the flexible substrate. However, I envisage the future will become flexible.

Q: How will P-OLEDs fare against other lighting technologies (LEDs for example)?

These are compatible ssl technologies and not competitors. An holistic solution to building design based on ssl solutions will almost certainly incorporate both lighting technologies, each addressing their unique applications….and maintained by a renewable energy source.

Q: What do you think are the main challenges for the OLED lighting industry?

The challenge to produce a cost effect p-oled luminaire is immense, as uniformity in colour, brightness and life are too. These can only be achieved through well controlled and well understood manufacturing processes. If p-oled or oled technologies are to be successful the commercial aspects can not be ignored…find out the needs and wants of the customer, and work with them to produce a product they ask for. Sell the benefits on offer, not the technology. This sounds simple, straight forward and obvious, but not natural to technologists.

Q: Where do you see OLED lighting in 3 years? When do you think we'll actually be able to buy an OLED "lamp"?

Certainly materials and device architectures will be in a position to challenge the most in-efficient fluorescent luminaries within this 3 year timescale, but not on selling price. Therefore develop the market opportunities suitable for the products that will be capable of been produced. As market pull becomes stronger the inevitable drive to reduce costs will happen, and the market size will grow accordingly.

OLED lamps are now available…OSRAM and Philips. But I do not have visibility of delivery time schedules and purchase price (yet).

Geoff - thank you for this interview. I hope TOPLESS will be a successful project, and I hope we'll get updates on your achievements soon.

Kyulux - Hyperfluoresence OLED emittersKyulux - Hyperfluoresence OLED emitters