Ryoji Nomura

P-185: Low-Drive-Voltage OLEDs with a Buffer Layer Having Molybdenum Oxide

In this paper, we introduce a useful composite layer, comprising hole-transporting materials with molybdenum oxide. By using the composite as a buffer layer on an anode, an OLED with low drive voltage can be obtained, and pixel defect formation can be effectively suppressed.

P-132: Long-Lived Deeply Red Phosphorescent OLEDs Based on Electrochemically Stable Ir Complexes

We have developed novel Ir complexes having quinoxaline structure in their ligands. These Ir complexes showed very high electrochemical stability. The OLEDs based on these Ir complexes exhibited deep red emission, and the luminance half-decay time of the device is estimated to exceed 50,000 hours at an initial luminance of 500 cd/m2.

69.3: Polymer/Metal‐Oxide Composite: A Novel Buffer Layer for Solution‐Processible OLEDs

We developed a novel polymer-metal oxide composite which is suitable as a buffer layer for solution-processible OLEDs. The composite, which consists of vanadium oxide and an amine-containing polymer, was fabricated by a sol-gel technique. It is possible to create Ohmic contact between the composite and electrodes, and this enabled the production of OLEDs with low driving voltage and high current efficiency.

64.4: High-Performance OLEDs Based on a New Class of Ir Complexes Bearing Pyrazine Structures in Their Ligands

We have developed novel Ir complexes having pyrazine structures in their ligands. The OLEDs based on these complexes showed unique properties and high performance. In particular, the red OLED achieved an extremely high efficiency of 30 cd/A with CIE color coordinates of (x, y) = (0.65, 0.35), and the luminance half-decay time was estimated to be about 100,000 hrs at an initial luminance of 1,000 cd/m2.

P-191: Novel Bipolar Materials Tailored for Phosphorescent OLEDs

We synthesized novel bipolar materials suitable for acting as host materials of phosphorescent organic light-emitting diodes (OLEDs). Our molecular design strategy involves combining electron- and hole-transporting components to produce a well-balanced carrier transportability, which contributes to an increase in efficiency and a decrease in operation voltage of green and red phosphorescent OLEDs.