title: The origin of the improved efficiency and stability of triphenylamine-substituted anthracene derivatives for OLEDs: a theoretical investigation.
abstract: Herein, we describe the molecular electronic structure, optical, and charge-transport properties of anthracene derivatives computationally using density functional theory to understand the factors responsible for the improved efficiency and stability of organic light-emitting diodes (OLEDs) with triphenylamine (TPA)-substituted anthracene derivatives. The high performance of OLEDs with TPA-substituted anthracene is revealed to derive from three original features in comparison with aryl-substituted anthracene derivatives: 1) the HOMO and LUMO are localized separately on TPA and anthracene moieties, respectively, which leads to better stability of the OLEDs due to the more stable cation of TPA under a hole majority-carrier environment; 2) the more balanceable hole and electron transport together with the easier hole injection leads to a larger rate of hole-electron recombination, which corresponds to the higher electroluminescence efficiency; and 3) the increasing reorganization energy for both hole and electron transport and the higher HOMO energy level provide a stable potential well for hole trapping, and then trapped holes induce a built-in electric field to prompt the balance of charge-carrier injection.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, PR China.
authors.forename: Bing
authors.initials: B
authors.lastname: Yang
authors.forename: Soo-Kang
authors.initials: SK
authors.lastname: Kim
authors.forename: Hai
authors.initials: H
authors.lastname: Xu
authors.forename: Young-Il
authors.initials: YI
authors.lastname: Park
authors.forename: Houyu
authors.initials: H
authors.lastname: Zhang
authors.forename: Cheng
authors.initials: C
authors.lastname: Gu
authors.forename: Fangzhong
authors.initials: F
authors.lastname: Shen
authors.forename: Chunlei
authors.initials: C
authors.lastname: Wang
authors.forename: Dandan
authors.initials: D
authors.lastname: Liu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Liu
authors.forename: Muddasir
authors.initials: M
authors.lastname: Hanif
authors.forename: Shi
authors.initials: S
authors.lastname: Tang
authors.forename: Weijun
authors.initials: W
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Jiacong
authors.initials: J
authors.lastname: Shen
authors.forename: Jong-Wook
authors.initials: JW
authors.lastname: Park
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Ma