|Lighting manufacturer Osram has reported new R&D results for OLED development, including a laboratory sample with an efficacy of 87 lm/W.
The German company described this as “a key breakthrough.” Thomas Dobbertin, head of OLED technology at Osram, said: “For the first time we have managed to obtain such high efficiency whilst retaining both aesthetic and technological characteristics such as lifetime, robustness and extreme flatness in a thin-film approach – in other words, we have given the panel the characteristics that are also central for future series production.”
Osram said that the measurement was performed under application-oriented conditions in an integrating sphere, without the use of macro extractors – these are lenses that can be used to extract more light and therefore optimize the measurement results.
The 87 lm/W result was measured at a brightness of 1000 cd/m2 and a color temperature of approximately 4000K. OLED efficacy is strongly dependent on brightness. The laboratory sample also achieved almost 75 lm/W at 5000 cd/m2.
The R&D sample used organic functional material that has already been tested in pilot manufacturing, which enables “product-relevant lifetimes,” says Osram, although no figures were provided. The company says that plans for industrialization are already being evaluated.
The OLED laboratory sample was prepared using a pure thin-film approach. The current was distributed evenly over the active surface using a special injection electrode on the light-generating surface. This offers homogenous light density from every angle. The aesthetic impression is not disrupted by visible electrode structures.
OLED research at OSRAM is funded via the TOPAS 2012 project funded by the German Federal Ministry of Education and Research (reference no. 13N10474). The focus of the research work of TOPAS 2012 is upon the development of OLED as the lighting of the future. “With our new peak value we have taken a major step towards our goal of achieving 100 lm/W,” says Thomas Dobbertin.