New levels of efficiency for white OLEDs
Late in 2007, OSRAM announced it had developed a unique, transparent white organic light emitting diode (OLED). Now the company has achieved record values of efficiency and lifetime while maintaining the brightness of warm white OLEDs.
OSRAM’s laboratory researchers have demonstrated for the first time the ability to improve two crucial OLED characteristics simultaneously: efficiency and lifetime. Up to now, higher efficiency meant a shorter lifespan, and vice-versa. The OSRAM team reached a real milestone for warm white OLEDs with efficiency of 46 lm/W (CIE of 0.46/0.42 measured in the integrated sphere) and a 5,000-hour lifetime, at a brightness of 1,000 cd/m². The color rendering index (CRI) of the almost 100 cm² prototype is 80. By March 2009, the researchers expect that a demonstrator for an energy-saving flat OLED light module comprising several tiles will be able to deliver an overall luminous flux of 500 lm from a power consumption of less than 10W.
The breakthrough in technology means that flat OLED light sources are nearing the values of conventional lighting solutions, thus becoming attractive for a wide variety of applications. With their pleasant diffused light – the color of which can be individually controlled – OLEDs could enhance premium lighting design elements such as light tiles that can be attached to any surface. OLED light sources are particularly attractive in industries such as interior design. This is due to their special properties as flat light sources and ability to offer a high quality of light and make a real impression in illuminated wall coverings, atmospheric canopies of light, and light partitions. This breakthrough achievement in OLED lighting is a result of the OPAL (Organic Phosphoresce Diodes for Applications on the Lighting Market) research project. OPAL is an initiative launched by the German Federal Ministry for Education and Research (BMBF) and coordinated by OSRAM, with the aim of producing efficient OLEDs in large numbers at reasonably low cost.