technology

A single pixel showing electroluminescence with spatial RGB colouration through deposition of multiple layers and mask-patterning.
Photograph; Mike Park of the University of Hull

OLEDs are a fast emerging field that is tipped to be one of the break-through technologies in the next 1-5 years. They will be seen in mobile devices, TV and laptop flat panel displays and lighting applications in the very near future. There are many benefits to the technology over existing systems including efficiency, power consumption and brightness.

There are also some technical issues with these new materials especially in their production and manufacture on large scales.

There are several approaches to producing OLED materials, each has their individual benefits and drawbacks. The Polar OLED technology can be applied to almost any approach and provides additional benefits, or a complete alternative. Flexibility in design is our strength.

The small molecule OLED (sm-OLED) approach gives excellent pixel density, colour quality and lifetime although the cost of production is relatively high and only possible onto glass substrates. This is because the production process utilizes a high temperature vacuum deposition step that is energy intensive and not suitable for plastic substrates.

The competing polymer OLED (p-OLED) system can be produced using ink-jet printing methods by solvent printing of the light emitting polymer. This gives a much cheaper route to manufacture but gives rise to problems with pixel density and layered systems. The lifetime of these devices is often not as good as the sm-OLED approach.

Polar OLED uses an altogether different approach. We use liquid crystal based polymer networks. Liquid crystals are the ‘fourth state of matter’ and were originally developed at the University of Hull, the home of Polar OLED. By using these materials, we are able to print or cast using solvents, the light emitting or charge transport layer. By then exposing this to UV or other suitable radiation, the Polar OLED material is cross-linked forming an insoluble layer. By using lithographic techniques, sub-micron resolution patterning is possible. By forming the insoluble layer, additional layers can then be added using different colour materials or patterns as required. Fully RGB devices have been demonstrated already.

This technology allows for high quality displays on both plastic or glass substrates as in the p-OLED approach but without the high cost of manufacture associated with the sm-OLED system.

Polar OLED materials have use in a number of applications;


OUR APPROACH;

Polar OLED Ltd


Alternatively, Polar OLED materials can be customised for use as photoalignment or charge transport layers –including tailoring for desired energy levels and polymerisation conditions. Utilising their flexible processability they can be used in conventional printing approaches as is demonstrated in our presentation.

For more information on our materials and process, please see our company presentation here