Programme details

The 2003 Descartes Prize went to a project bringing a new display technique, led by the English scientist Richard Friend of the University of Cambridge.
The initial discovery was dued to a happy combination of hard research and chance. The original work was to see whether we could make semi conducted devices like diodes or transistors using these polymers and we discovered by chance that we could get light coming out from a diode so we discovered we had a way to make displays.

The Team

This research has gathered teams from
The Chancellor, Masters and Scholars of the University of Cambridge, Cambridge Display Technology, United Kingdom, Materia Nova in Mons, Belgium, the Linköping University, Sweden, Philips Electronics in Eindhoven, The Netherlands and Covion in Frankfurt, Germany.

The Principle

This project is in the area of semiconductors, most semiconductors are silicon based.
The objective was to have a completely different set of materials to use as semi conductors.
Therefore we’ve created plastics or polymers which behave as semiconductors and actually allow us to make very good light emitting diodes which we can then use for displays.

The Method

We start with a bottle of solution of the light emitting polymer in order too make a light-emitting diode. We take some of that liquid and we coat it onto the bottom substrate and allow the solvent to evaporate off. We put down the top layer of metals which we evaporate in a vacuum. This sandwich of metal, polymer, semiconductor, metal, has to be encapsulated to keep the air out of it and then we wire it up with putting a voltage between the bottom and the top electrodes and we measure the light as it comes out.
To make screens that can display images, the different layers of polymers are sandwiched between two transparent layers of column patterned electrodes.

Development

The best way to make progress is to have a very good balance between empiricism, being a good observer of what actually happens in the laboratory, and then feeding that back into understanding and into modelling, what is likely to happen to the colour.

Spinn Off

After making research materials we want to scale up slightly and this is where we do the scale up to about a hundred grams, which doesn’t sound like a lot but it will actually make, for example, five hundred thousand mobile phones which is quite a good scale for sub development models.

Conclusion

The novelty in this research is in two areas. First the effects from the materials, this whole class of plastics can function as semiconductors and real semiconductor light emitting diodes can be made with them.
Second the whole manufacturing technology for depositing these diodes in factor for the surface of the display.