title: Bipolar Host Materials for Organic Light-Emitting Diodes.
abstract: It is important to balance holes and electrons in the emitting layer of organic light-emitting diodes to maximize recombination efficiency and the accompanying external quantum efficiency. Therefore, the host materials of the emitting layer should transport both holes and electrons for the charge balance. From this perspective, bipolar hosts have been popular as the host materials of thermally activated delayed fluorescent devices and phosphorescent organic light-emitting diodes. In this review, we have summarized recent developments of bipolar hosts and suggested perspectives of host materials for organic light-emitting diodes.
authors.affiliation: School of Chemical Engineering Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu Suwon, Gyeonggi, 440-746, Republic of Korea.|School of Mechanical Engineering Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu Suwon, Gyeonggi, 440-746, Republic of Korea.
authors.forename: Kyoung Soo
authors.initials: KS
authors.lastname: Yook
authors.affiliation: School of Chemical Engineering Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu Suwon, Gyeonggi, 440-746, Republic of Korea.
authors.forename: Jun Yeob
authors.initials: JY
authors.lastname: Lee
keywords: bipolar hosts; donor-acceptor systems; doping; molecular electronics; organic light-emitting diodes