RGB materials for organic light-emitting displays

摘要

Abstract: We review our research activities in the field of organic light-emitting diodes (OLED's) aiming practical applications to full-color flat panel displays. The central issue of the research is to develop the suitable materials. The side-by- side patterning of discrete RGB sub-pixels without using dopants is straightforward and attractive from aspects of energy conversion efficiencies and productivity in comparison with the other methods proposed so far. We have been concerned in emitting material systems which emit R, G and B lights respectively using a common set of a hole-injecting layer, a hole-transporting layer (HTL), and electron transporting layer (ETL). Our research goal is to develop the good performance OLED matrices without using fluorescent dopants. Green light is obtained with an ordinary single hetero-structure. Blue light is achieved from the hole-transporting layer by inserting a hole-blocking layer between the HTL and the ETL. The maximum emission intensity was about 10,000 cd/m$+2$/ at the applied voltage of 9.5 V and the color was as good as (0.15, 0.16) in the CIE chromaticity coordinates. Our current research focuses on new red materials, which are suitable for the layered structures. These materials systems would provide full-color display panels with the minimum number of materials used. !14