Joint research project So-Light gives OLED technology a boost

January 31, 2013 // By Christoph Hammerschmidt
Eleven German OLED companies and research institutions successfully completed the So-Light project which addressed the complete value chain, from primary materials to lighting applications. Within the project several promising innovations have been created which now will be introduced to markets.

In the project, results were achieved in a large number of technology segments, including materials, processes and panel technologies.

In the field of 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.
 In addition, 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).

In the processes arena, semiconductor equipment manufacturer Aixtron and the Fraunhofer research institute for organic electronic materials, COMEDD, jointly optimized the OVPD (Organic Vapour Phase deposition) process on a Gen2 substrate size. 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.

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.

Siteco manufactured a suspension luminaire containing OLEDs, point source LEDs and an exterior luminaire for building façade integration And BMG MIS developed a thin OLED backlight for LCD-signage application. These elements form the basis for a modular construction of ultra thin large