An alternative to conventional lighting

UK company Thorn Lighting is leading a project to develop organic light-emitting diode (OLED) materials and efficient device structures for large area lighting applications.

Partners in the project are the University of Durham (Photonics Materials Institute) and Cambridge Display Technology (CDT).

CDT, through its Sumation joint venture, will provide significant knowledge and experience in the field of light-emitting conjugated polymers as well as delivering polymer-based OLED materials, device architectures and testing. Durham University has developed one of the most important academic alliances between physicists and chemists in Europe, with unique facilities for studying energy transfer mechanisms in both polymer materials and device structures. "The materials we are hoping to develop will give high brightness, high efficiency white light, which could replace general-purpose lighting," said Dr Geoff Williams, OLED group leader of Thorn.

Wafer-thin OLED panels are one of the key technologies touted to displace conventional light sources, such as fluorescent and incandescent lamps. OLEDs offer the potential for large area white lighting. The materials can be printed onto either solid or flexible glass or plastic substrates with long life (20,000 hours), reduced energy consumption and less waste (1 kg of material will coat 10,000,000 m² of lighting area). The electrical efficiency should be close to fluorescent tubes.

"The target is 50 lumens per watt in four to five years, with a colour rendering index (CRI) better than standard fluorescent lamps. The eventual target is 150-200 lm/W. In 2015, we will be near this level and by 2020, OLED lighting will be the first choice," said Williams.

"The challenge does not only exist for the materials and devices, but the Thorn team will strive to design new Sigma 6 manufacturing and quality control processes capable for this emerging technology."

The project will allow Thorn to challenge traditional lighting philosophies and will point the way towards environmentally friendly artificial lighting, based on low-voltage DC devices and sustainable renewable energy sources.