Osram reports warm-white OLED with 46 lm/W efficiency

As part of the OPAL research project, Osram has simultaneously achieved long lifetime and high efficiency.

Osram has reported further progress in the development of energy-efficient OLEDs by achieving an efficiency of 46 lm/W, a brightness of 1000 cd/m2 and a lifetime of more than 5000 hours.

The warm-white OLED prototype panel measuring almost 100 cm2 had a color rendering index of 80. The CIE color coordinates were (0.46, 0.42).

Osram says that for the first time it has been possible to improve two crucial OLED characteristics – lifetime and efficiency – simultaneously. Usually, higher efficiency means shorter life, and vice versa.

Karsten Heuser, director of OLED Lighting Technology at Osram Opto Semiconductors, said, “Our development team has reached a real milestone for warm white OLEDs. With this significant increase in efficiency and life, OLED flat light sources are approaching the values of conventional lighting solutions and are therefore becoming attractive for a wide variety of applications.”

By March 2009, Osram expects that the development should be so far advanced that a demonstrator for an energy-saving OLED flat light module comprising several tiles will be able to deliver an overall luminous flux of 500 lm from a power consumption of less than 10 W.

OLED light sources are likely to find use in applications that can make use of flat light sources with high quality of light, for example in illuminated wall coverings, light partitions, and atmospheric canopies of light. With their pleasant diffused light, OLEDs are likely to enhance the premium design segment.

For widespread applications it will be necessary to produce efficient OLEDs in large numbers at reasonably low cost – an essential objective of the research project.

Osram's results were achieved as part of the “500 lm Multi-OLED Module” project under the OPAL research consortium. This project is focusing on the optimization of the layer system comprising small molecules, in which the layers are produced by means of vacuum evaporation. In addition to Osram, this project involves Siemens Corporate Technology, the universities in Darmstadt, Braunschweig and Augsburg and the IPMS Dresden.

The OPAL (Organic Phosphoresce Diodes for Applications on the Lighting Market) project was launched by the German Federal Ministry for Education and Research (BMBF) to strengthen the OLED position in Germany.

OPAL's purpose is to create a research platform to develop the underlying technology blocks for subsequent series production of OLEDs and their widespread marketing in the future. As the coordinator, Osram says it is working at full pace on the development of high-efficiency OLED light sources.

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