Molecular Crystals and Liquid Crystals, Vol.471, 261-268, 2007
Multi-color organic light emitting panels using self-aligned ink-jet printing technology
We have investigated multi- color organic light emitting panels using a self- aligned ( SA) ink- jet printing ( IJP) technology. Emission ink with phosphorescent materials of an iridium( III) bis( 2-( 2'- benzothienyl) pyridinato- N, C3') ( acetylacetonate) ( Btp(2)Ir( acac)) for red, an fac- tris( 2-( p- tolyl)- pyridine) iridium ( Ir( tpy)(3) for green, and an iridium( III) bis( 2-( 4,6- difluorophenyl) pyridinato- N, C2') picolinate ( FIrpic) for blue were printed on an indium- zinc- oxide ( IZO) coated glass substrate covered with an insulating poly- methylmethacrylate ( PMMA) layer. The PMMA was dissolved in a solvent of ink, then, emission region was formed at the same position as that of the ink- jet- printed region. The device structure was IZO/PEDOT/PMMA ( 30 nm)<- Ink/BCP ( 20 nm)/ LiF ( 1 nm)/Al ( 70 nm). Luminescence of the device with red, green and blue emission materials, were 655 2,640 and 857 cd/m(2), respectively. We have also demonstrated 150 ppi resolution of multi- color light emitting panels using the self- aligned IJP method.
Keywords:ink-jet printing method;light emitting logo panels;organic phosphorescent device;self-alignment technology;small molecular solution-process