PDF Basket
Organic light-emitting diodes, or OLEDs, include a layer of a thin, organic compound that can emit light in response to an electric current. Light from OLEDs is more uniform, produces less glare and is closer to natural light than alternatives such as LEDs and traditional light-bulbs. OLEDs also produce very little heat, and their lack of bulk and flexibility makes them an attractive technology for the likes of lighting manufacturers, designers and architects.
The EU-funded LEO project set out to develop and manufacture high-performance, flexible and low-cost OLEDs that could meet future requirements in the house-building and automotive sectors. Examples of their use include improved mood lighting in homes and offices as well as backlighting for car dashboard displays.
‘To maximise the potential of OLEDs, we aimed to increase their performances in terms of brightness, colour, energy efficiency and lifespan while decreasing the environmental impact of their manufacture, use and end of life by improving their recyclability,’ says project coordinator Etienne Quesnel from the Commissariat à l’Énergie Atomique et aux Énergies Alternatives, France. ‘We also needed to give them new functionalities to provide designers with the opportunity to create innovative new products for the market place.’
Marketable products
LEO succeeded in developing a number of OLED demonstrators that have generated several marketable products. One major innovation has been to create a mounting for OLEDs made out of steel foils as an alternative to plastics. An industrial manufacturer has shown an interest in making the product. The steel foils could also be used in other markets, for example as mountings for solar-power cells. In addition, there is an environmental dividend with this innovation as steel is easier to recycle than the plastic alternatives.
One of the project’s industrial partners has also made more efficient and environmentally friendly light-emitting materials for OLEDs that contain no scarce metals. The company has already signed a partnership with lighting display manufacturers in Asia.
In addition, LEO made an important breakthrough by solving a problem that has hampered the development of this technology. Organic electronic compounds are extremely vulnerable to environmental factors. In response, the project developed a novel composite material that is both flexible and highly resistant to moisture.
‘This new material is particularly well adapted to the OLED market and more generally to organic electronics,’ says Quesnel. ‘Since the end of LEO project, several industrial companies worldwide have shown an interest in this technology – both in the field of lighting but also in the development of OLED micro-displays.’
Improved safety
Through its work, the LEO consortium came up with other innovations, including the use of inkjet technology as a way of saving on materials when manufacturing OLEDs. Moreover, by using less toxic materials – epoxy instead of polyimide – in constructing the steel foils, the project team has made OLEDs safer for human health.
The project consortium brought together research institutes and leading European materials and lighting manufacturers. By publishing articles in a number of scientific journals, members have added to knowledge about some of the basic chemical and physical characteristics of OLED technology, and four early-stage researchers were hired during the project for training.