A wet- and dry-process feasible carbazole type host for highly efficient phosphorescent OLEDsElectronic supplementary information (ESI) available. See DOI: 10.1039/c5tc02889b

• Main Authors: Jou, Jwo-Huei, Sahoo, Snehasis, Kumar, Sudhir, Yu, Hui-Huan, Fang, Po-Hsun, Singh, Meenu, Krucaite, Gintare, Volyniuk, Dmytro, Grazulevicius, Juozas Vidas, Grigalevicius, Saulius
• Format: Journal Article
• Language: English
• Published: 26.11.2015
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c5tc02889b

A wet- and dry-process feasible host material is crucial to realize, respectively, low cost roll-to-roll fabrication of large area and high performance organic light-emitting diodes (OLEDs) with precise deposition of organic layers. We demonstrate in this study high efficiency phosphorescent OLED devices by employing a newly synthesized carbazole based host material 1,6-bis[3-(2-methoxy-3-pyridinyl)carbazol-9-yl]hexane (compound 5 ). Moreover, two other carbazole hosts 1,6-bis[3-(6-methoxy-3-pyridinyl)carbazol-9-yl]hexane (compound 4 ) and 3,6-di(2-methoxy-3-pyridinyl)-9-ethylcarbazole (compound 6 ) are also synthesized for comparison. By doping a typical green emitter fac tris(2-phenylpyridine)iridium (Ir(ppy) 3 ) in compound 5 , for example, the resultant wet-processed device exhibits at 100 cd m −2 a current efficiency of 27 cd A −1 and a power efficiency of 16.1 lm W −1 . The dry-processed device shows a current efficiency of 61 cd A −1 and a power efficiency of 62.8 lm W −1 . The high efficiency may be attributed to the host possessing an effective host-to-guest energy transfer, effective carrier injection balance, and the device architecture enabling excitons to generate on both the host and the guest. A wet- and dry-process feasible host material is crucial to realize, respectively, low cost roll-to-roll fabrication of large area and high performance organic light-emitting diodes (OLEDs) with precise deposition of organic layers.