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Endowing TADF luminophors with AIE properties through adjusting flexible dendrons for highly efficient solution-processed nondoped OLEDs† †Electronic supplementary information (ESI) available: Synthesis and characterization details, NMR spectra of compounds, CV curves, SEM and AFM images. Photophysical properties and supplementary device performance. See DOI: 10.1039/d0sc02194f

ABSTRACT: Construction of core–dendron TADF emitters systematically: changing the behaviour of chromophores from aggregation-caused quenching to aggregation induced emission to develop high-performance fully solution-processed nondoped OLEDs. The amalgamation of thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) properties, termed AIE-TADF, is a promising strategy to design novel robust luminescent materials. Herein, we transform 2,3,4,5,6-penta(9H-carbazol-9-yl)benzonitrile (5CzBN) from an ACQ molecule into an AIEgen by simply decorating the 5CzBN core with alkyl chain-linked spirobifluorene dendrons. By increasing the number of flexible dendrons, these materials can not only show obvious AIE-TADF characteristics and uniform film morphology, but can also exhibit better resistance to isopropyl alcohol, which are beneficial to fully solution-processed OLEDs. Notably, 5CzBN-PSP shows great device efficiency with an external quantum efficiency (EQE), current efficiency and power efficiency of 20.1%, 58.7 cd A–1 and 46.2 lm W–1, respectively and achieved record-breaking efficiency in solution-processed nondoped OLEDs based on AIE emitters. This work demonstrates a general approach to explore new efficient emitters by the marriage of AIE and TADF which could potentially improve their performance in various areas.

SUBMITTER: Liu D

PROVIDER: S-EPMC7499814 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature

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