The European OLLA project* have released a discussion paper on the measurement of luminous efficacy for OLED light sources. The goal is to set a measurement standard especially designed for flat light sources. This standard makes a fair comparison of OLED research results possible. The white paper can be downloaded from the OLLA website.
The efficiency of the transformation of electrical energy into visible light is one of the crucial parameters for lighting applications. Considering the fact that 19% of the worldwide energy consumption is accounted for lighting applications, there is a clear demand for all lighting technologies to achieve greater efficiency.
Whilst conventional lamp technologies already have derived standards for the measurement of lighting efficiency, this field is still open for OLED light sources. Therefore, the OLLA project white paper describes clearly the definition of OLED efficiency and how efficacy has to be measured for flat light sources.
"It is very important for a new lighting technology like OLEDs to have early clear standards defined for its most important light parameters," said Dr. Karsten Diekmann of Osram Opto Semiconductors and co-author of the white paper. "The OLED lamp as a large-area, flat light source bears already a high degree of final luminary characteristics. Therefore we want to set a standard for its efficacy, so that all early adopters of OLED lighting technology have a good expectation of what light stream they can expect".
The development of OLED lighting technology is subject of worldwide attention. The OLLA project delivered in May this year OLEDs with an efficacy of 25 lm per Watt, which is twice as efficient as a standard incandescent lamp. Several other groups reported even higher figures, but without mentioning how these figures were measured.
"This OLLA white paper is another initial, but important next step towards the development of an OLED lighting industry in Europe," said Peter Visser, project manager of the OLLA project at Philips Lighting. "It supports the standardization of performance and measurement criteria for OLED light sources, which helps to build market acceptance for this light source. We hope that all research groups take notice of this paper, and publish their next results on this OLLA basis. Therefore we welcome all experts in the field to discuss our proposal," Visser concluded.
OLEDs are flat solid-state light sources made from hydrocarbon complexes. OLEDs directly convert electricity into visible light. OLED technology is worldwide recognized as a very promising next lighting technology for professional and domestic applications. OLED materials are based on various organics. Together with inorganic LEDs, OLEDs have the potential for considerable energy savings in lighting applications.
* 'OLLA' stands for high brightness Organic LEDs for ICT & next generation Lighting Applications
For more attend Printed Electronics USA.
Source of top image: The OLLA Project