Multi-Color Organic Light Emitting Panels Using Self-Aligned Ink-Jet Printing Technology

Abstract

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) (Btp₂Ir(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/m², respectively. We have also demonstrated 150 ppi resolution of multi-color light emitting panels using the self-aligned IJP method.