title: Design of efficient thermally activated delayed fluorescence materials for pure blue organic light emitting diodes.
abstract: Efficient thermally activated delayed fluorescence (TADF) has been characterized for a carbazole/sulfone derivative in both solutions and doped films. A pure blue organic light emitting diode (OLED) based on this compound demonstrates a very high external quantum efficiency (EQE) of nearly 10% at low current density. Because TADF only occurs in a bipolar system where donor and acceptor centered (3)ππ* states are close to or higher than the triplet intramolecular charge transfer ((3)CT) state, control of the π-conjugation length of both donor and acceptor is considered to be as important as breaking the π-conjugation between them in blue TADF material design.
authors.affiliation: Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Qisheng
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Shizu
authors.forename: Shuping
authors.initials: S
authors.lastname: Huang
authors.forename: Shuzo
authors.initials: S
authors.lastname: Hirata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyazaki
authors.forename: Chihaya
authors.initials: C
authors.lastname: Adachi