title: Hybridization and de-hybridization between the locally-excited (LE) state and the charge-transfer (CT) state: a combined experimental and theoretical study.
abstract: Excited state properties play a key role in the photoluminescence (PL) and electroluminescence (EL) performance of organic light-emitting diode (OLED) materials. The solvatochromic effects were observed in a series of triphenylamine (TPA)-phenanthroimidazole (PI) derivatives with the increase of solvent polarity, accompanied by the transformation of an excited state character from the locally-excited (LE) state to the charge-transfer (CT) state in the emission spectra. The excited state properties were systematically investigated in these donor-acceptor systems using time-dependent density functional theory (TD-DFT). The hybridization and de-hybridization processes between LE and CT states were resolved with an increasing number of phenyls along horizontal and vertical directions, respectively. We provide a novel insight into the fine modulation of the excited-state characters and compositions in the donor-acceptor system for the new-generation, low-cost and high-efficiency fluorescent OLED materials.
authors.affiliation: State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P. R. China. yangbing@jlu.edu.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Shitong
authors.initials: S
authors.lastname: Zhang
authors.forename: Yuyu
authors.initials: Y
authors.lastname: Pan
authors.forename: Liang
authors.initials: L
authors.lastname: Yao
authors.forename: Haichao
authors.initials: H
authors.lastname: Liu
authors.forename: Yachen
authors.initials: Y
authors.lastname: Guo
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gu
authors.forename: Bing
authors.initials: B
authors.lastname: Yang
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Ma