Molecular design of highly effective thermally activated delayed fluorescence emitters based on ortho-substituted donor-acceptor-donor pyridinecarbonitrile derivatives and their application for high-performance OLEDs

Choi, Shin Hyung; Lee, Chan Hee; Adachi, Chihaya; Lee, Sae Youn

doi:10.1016/j.dyepig.2019.107775

Cited by 7 publications

(2 citation statements)

References 32 publications

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“…Recently, thermally activated delayed fluorescence (TADF) materials have been researched as alternatives to fluorescence and phosphorescence materials in OLEDs because of their high η ST through reverse ISC (RISC) from the T 1 to the S 1 state, resulting in a maximum η int of 100% [ 12 , 13 , 14 , 15 , 16 ]. A small S 1 and T 1 state energy gap (Δ E ST ) attained by minimizing the overlap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) can lead to efficient RISC.…”

Section: Introductionmentioning

confidence: 99%

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Highly Effective Thermally Activated Delayed Fluorescence Emitters Based on Symmetry and Asymmetry Nicotinonitrile Derivatives

et al. 2022

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In this study, we developed two thermally activated delayed fluorescence (TADF) emitters, ICzCN and ICzCYP, to apply to organic light-emitting diodes (OLEDs). These emitters involve indolocarbazole (ICz) donor units and nicotinonitrile acceptor units with a twisted donor-acceptor-donor (D-A-D) structure for small singlet (S1) and triplet (T1) state energy gap (ΔEST) to enable efficient exciton transfer from the T1 to the S1 state. Depending on the position of the cyano-substituent, ICzCN has a symmetric structure by introducing donor units at the 3,5-position of isonicotinonitrile, and ICzCYP has an asymmetric structure by introducing donor units at the 2,6-position of nicotinonitrile. These emitters have different properties, such as the maximum luminance (Lmax) value. The Lmax of ICzCN reached over 10000 cd m−2. The external quantum efficiency (ηext) was 14.8% for ICzCN and 14.9% for ICzCYP, and both achieved a low turn-on voltage (Von) of less than 3.4 eV.

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Section: Introductionmentioning

confidence: 99%

“…Figure S8: Streak images and time-resolved PL spectra of 12 wt% (a) ICzCN :PPF and (b) ICzCYP :PPF co-deposited films. Table S2: Photophysical properties of ICzCN and ICzCYP in solution, neat film and 12 wt% doped film in PPF host [ 12 , 20 , 21 , 31 ].…”

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confidence: 99%