New record for lifetime of organic light-emitting diodes
The Institute for Applied Photophysics (IAPP) at the Technical University of Dresden has now announced a new record for the service life of organic light-emitting diodes. The light elements, which were developed by Rico Meerheim and the IAPP's OLED working group, have an estimated lifespan of up to ten million hours, which is 1123 years. The previous record by an American company was 1.5 million hours.
Organic light-emitting diodes (OLED) are increasingly being installed in the displays of mobile phones, digital cameras or handheld computers. In the future, OLEDs will also play an increasingly important role in screens and lighting. The service life is so relevant because it decreases with increasing brightness. In order to be able to develop much brighter light-emitting diodes in the future, the longest possible service life is crucial as a precautionary measure. At the moment, the diodes are about as bright as a computer screen. In addition, the power consumption is very low and the efficiency - conversion of electrical energy into light - at eleven percent is more than twice as high as that of an incandescent lamp (five percent).
In the case of the light-emitting diodes developed in Dresden, the scientists stacked organic dyes (with different electronic properties) in layers in a specific sequence. In addition, the electronic properties of the organic materials used were specifically modified. Small charge carriers are trapped in the layers and the diode lights up. The enormous service life could be achieved in combination of design and material properties.
"Organic light-emitting diodes will eventually replace liquid crystal screens," explains Karsten Walzer, head of the working group responsible for OLED development. Screens with OLEDs are more energy efficient and brighter. In addition, the diodes take up very little space in displays and the viewing angle is irrelevant. An energy-saving variant of ceiling lighting will also be possible in the future with OLEDs. Whether in brick form or as a light panel: one square meter of organic light-emitting diodes would currently be needed to illuminate a twenty square meter room.
A commercial implementation of the research results is planned with the company Novaled AG, which was spun off from the TU Dresden. © Technical University of Dresden