High-color-rendering pure-white phosphorescent organic light-emitting devices employing only two complementary colors

✍ Scribed by Chih-Hao Chang; Chung-Chia Chen; Chung-Chih Wu; Sheng-Yuan Chang; Jui-Yi Hung; Yun Chi

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 469 KB
• Volume: 11
• Category: Article
• ISSN: 1566-1199
• DOI: 10.1016/j.orgel.2009.11.004

✦ Synopsis

We report successful fabrication of high-color-rendering pure-white phosphorescent organic light-emitting devices (OLEDs) by employing a true-blue iridium complex Ir(dfbppy)(fbppz) 2 and a wide-bandwidth yellow emitting osmium complex Os(bptz) 2 (dppee). The two-component phosphorescent white OLED exhibited a high color rendering index (CRI) of 81 and CIE x,y coordinates close to the ideal white emission (0.33, 0.33). By doping the yellow phosphors into the hole-transport layer and the electron-transport layer adjacent to the blue-emitting layer and thereby forming a triple-emitting-layer device structure, we obtained WOLED which exhibited rather stable colors at different biases/ brightnesses. Such high-CRI pure-white two-component WOLEDs yielded EL efficiencies of up to 9.5%, 22.9 cd/A, and 20 lm/W for the forward directions.