Dresden 2017 – wissenschaftliches Programm
CPP 7: Organic Electronics and Photovoltaics I: Light-Emitting Devices (joint session CPP/DS/HL, organized by CPP)
CPP 7.6: Vortrag
Montag, 20. März 2017, 12:15–12:30, ZEU 260
Ultrathin metal electrode for bottom-emitting OLEDs on buckled substrates — •Yungui Li, Toni Bärschneider, Paul-Anton Will, Yuan Liu, Simone Lenk, and Sebastian Reineke — Dresden Integrated Center for Applied Physics and Photonics Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, 01062 Dresden, Germany
We here report our investigations on nanometer thick, composite ultrathin metal electrodes used in organic light-emitting diodes (OLEDs) comprising buckled substrates. The thin metal electrodes are made of 1 nm molybdenum trioxide (MoO3), 2 nm gold, and 3-15 nm of silver. A composite electrode with 9 nm silver based on flat glass substrate shows a maximum transparency of about 80% at 455 nm and a sheet resistance of 10 Ω/sq. With reactive-ion etching process, a buckled surface with depths around 50 to 100 nm is designed to extract the trapped light of bottom-emitting OLEDs since total internal reflection in flat device. When the thin metal electrode is utilized for green bottom-emitting OLEDs, the devices show a maximum external quantum efficiency of 17.5% for buckled OLEDs while in contrast only 13.8% for flat devices. Compared to flat devices, buckled devices show the same level of leakage current and better color stability at different angles. The results confirm the high potential of composite thin metal systems as alternative electrode for OLEDs, with the capability of application for bottom- and top-emitting OLEDs on patterned surfaces.