title: Rational design of host materials for phosphorescent organic light-emitting diodes by modifying the 1-position of carbazole.
abstract: A novel carbazole moiety with bromine at the 1-position of carbazole was synthesized and four carbazole compounds derived from the 1-position modified carbazole were developed as the host materials for phosphorescent organic light-emitting diodes. The 1-position modified carbazole was coupled with another carbazole to prepare bicarbazole intermediates, which were substituted with 4,6-diphenyltriazine to yield four bicarbazole derivatives modified with the electron deficient diphenyltriazine unit. The triplet host materials showed high quantum efficiency above 20% and low driving voltage below 5.0 V at 1000 cd m(-2) in green phosphorescent organic light-emitting diodes.
authors.affiliation: School of Chemical Engineering, Sungkyunkwan University, Suwon, Gyeonggi 446-740, Republic of Korea. leej17@skku.edu.
authors.forename: Sung Moo
authors.initials: SM
authors.lastname: Kim
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Byeon
authors.forename: Seok-Ho
authors.initials: SH
authors.lastname: Hwang
authors.forename: Jun Yeob
authors.initials: JY
authors.lastname: Lee