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.
- An efficacy of 20lm per watt
- Colour temperature suitable for general white light applications (this varies according to customer requirements) between 2,700K to 17,000K.
- Large single pixel devices (no buzz bars)
- Minimal number of organic layers
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.
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