In the pursuit of environmentally-friendly lighting, organic LEDs have long been touted as an attractive option. They could be significantly more efficient than conventional lighting and unlike fluorescent tubing they don 't contain toxic mercury. Now, researchers in Germany have created the first LED from organic materials that is more efficient than traditional lighting.
Light emitting diodes emit monochromatic light when their electrons combine with holes to form “excitons”. Standard LEDs made from inorganic materials have already found widespread application in screens and commercial lighting because of their high efficiency. For example, the Water Cube swimming arena at last summer 's Beijing Olympics used nearly half a million red, green and blue LEDs.
In recent years researchers have also started to develop a new wave of LEDs using organic materials such as polymers. As well as being eco-friendly to dispose of, these LEDs also have the advantage of generating photons across a range of colours resulting in white light. Now, a team of physicists have redesigned the internal structure of organic LEDs to produce significantly brighter white light.