title: Novel ambipolar orthogonal donor-acceptor host for blue organic light emitting diodes.
abstract: Ambipolar triplet hosts comprising 1,2,4-triazole and carbazole in ortho-positions have been developed. The blue PHOLED has a high current efficiency of 47.1 cd A(-1), power efficiency of 41.2 lm W(-1), and low efficiency roll-off. The high efficiency was attributed to the successful control of π-conjugation through orthogonal arrangement of the substituents so that a wide T1-S0 gap could be maintained.
authors.affiliation: Department of Chemistry, Institute of Polymer Science and Engineering, Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University , 1 Roosevelt Road Section 4, Taipei 106, Taiwan, R.O.C., and Department of Photonics Engineering, Yuan Ze University , 135 Yuan-Tung Road, Chung-Li 32003, Taiwan, R.O.C.
authors.forename: Man-kit
authors.initials: MK
authors.lastname: Leung
authors.forename: Yu-Hsuan
authors.initials: YH
authors.lastname: Hsieh
authors.forename: Ting-Yi
authors.initials: TY
authors.lastname: Kuo
authors.forename: Pi-Tai
authors.initials: PT
authors.lastname: Chou
authors.forename: Jiun-Haw
authors.initials: JH
authors.lastname: Lee
authors.forename: Tien-Lung
authors.initials: TL
authors.lastname: Chiu
authors.forename: Hsin-Jen
authors.initials: HJ
authors.lastname: Chen