The German OLED project So-Light has been successfully completed. This 3.5 years, €14.7 million project (funded by the German Federal Ministry of Education and Research) addressed the complete value chain, from primary OLED materials through to OLED-lighting applications.
The So-light partners announced the following results:
New materials
§ Novaled and Sensient jointly developed a new p-doped hole transport system with potential for lower absorption and lower cost scaleability than previous materials. The jointly developed materials will be commercialized by Novaled.
§ Novaled made significant progress towards a fully air-stable n-doped electron transport layer. After more R&D work it is expected that this will lead to a commercial offering.
§ Sensient developed new host materials for OLED emitter layers which gave rise to efficiency enhancements in a reference OLED.
§ The University of Muenster, together with Sensient, synthesized new platinum(II)-complexes. Used as triplet emitters, they enabled outstanding high quantum efficiencies for Pt(II) complexes of up to 75% (for green) and high current efficiencies of up to 16cd/A (green-yellow colour)
Novel Processes
§ Aixtron and COMEDD jointly optimized the OVPD process on a Gen2 substrate size. The capability of this tool was demonstrated with the evaporation of the new p-HTL system developed by Novaled and Sensient.
§ In addition, Aixtron demonstrated a new high deposition rate process based on their novel STExS source concept. Evaporation rates of above 40 Angstrom/second were achieved for the p-HTL system with significantly reduced thermal exposure of the materials involved. This will allow much faster processing of sensitive organic materials compared to the current conventional process technology.
Novel panel-technologies:
§ LEDON OLED Lighting developed an efficient and robust electrical contacting technology which also enabled better system efficiency and homogeneity.
§ In addition the use of a special rear surface heat distribution unit gave rise to better OLED emission uniformity without materially altering the level profile of an OLED panel.
Novel optical technologies:
§ Fresnel Optics successfully processed an external flat primary optics directly on the rear surface of an OLED-panel including new features such as structured apertures or structured silvering.
- Novel qualification methods:
§ The University of Paderborn/L-LAB gathered photometric data on OLEDs specifically related to lifetime, lumen maintenance, illumination, color uniformity and UV degradation.
In addition, COMEDD's TABOLA OLED lighting panels have been used in three design studies:
§ HELLA made design studies for automotive indoor lighting and for a car rear-light with red OLEDs.
§ Siteco manufactured a suspension luminaire containing OLEDs, point source LEDs and an exterior luminaire for building façade integration.
§ BMB MIS developed a thin OLED backlight for LCD-signage application. These elements form the basis for a modular construction of ultra thin large area LCD-signage for the transportation business.
