Illuminating wallpaper

How would it be if, when you got home and switched the light on, the walls lit up? If, sitting in your living room, you pointed the remote control at the wallpaper and it played your favourite film? Or if newspapers were no longer printed on paper, but came through your letterbox as rolls of electronic paper with moving pictures? OLED technology is bringing this vision within reach. OLEDs are organic light emitting diodes. They consist of wafer-thin organic semiconducting polymer films – similar to a plastic film – from the chemical industry. Embedded between a transparent negative pole and a positive pole, these films light up when an electrical voltage is applied and can be used as large area lighting or as monitor or TV screens. They are already being used in displays for devices such as mobile phones and MP3 players. The German Federal Ministry of Education and Research (BMBF) has recognised the potential of this optical technology. Together with partners from universities, research institutes and industry, the BMBF is promoting research and development in the field of organic light emitting diodes.

Mood lighting

In the future, OLEDs could substantially influence how we live. Lighting based on organic light emitting diodes offers a number of benefits. OLEDs are flexible and can be hung in rooms like wallpaper. Connected to a power source, they light up in the colours and patterns required. They emit a pleasant, diffuse light which is softer than light bulbs or neon tubes. OLEDs can help create well-being and ambience with mood lighting – a romantic starry sky twinkling on the ceiling or changing springtime motifs on the wallpaper could brighten up rainy November days. This kind of atmospheric lighting remains for now, however, a vision for the future. Experts reckon that this technology will become affordable for a mass market in around 15 years time. The first OLED television screens will be available in the shops in three to four years at the earliest.

Achieving the breakthrough

There are still a few technical problems to be ironed out before these visions of the future can become reality. These relate to the material properties of OLEDs. This is where know-how in the field of chemistry comes into play. In particular the lifespan of these products still needs a lot of work, as the wafer-thin, flexible polymer films are sensitive to oxygen and moisture. This is why such displays are currently still encased in glass. The intensity of the colours and the short lifespan of the blue emitter also remain obstacles to their use in TV screens at present. 

Efficient energy consumption

Even if large-scale light sources or TV screens are still some way off being ready for primetime, it is already clear that OLEDs will use considerably less energy. They are substantially more efficient at transforming electricity into light, which means that OLED lighting will be significantly more energy efficient than normal incandescent and energy saving bulbs. Batteries in mobile devices such as laptops, mobile phones and digital cameras will last much longer. In future, you’ll be able to telephone, surf the internet on the go or take photographs for longer.