Solution‐Processed, Undoped, Deep‐Blue Organic Light‐Emitting Diodes Based on Starburst Oligofluorenes with a Planar Triphenylamine Core

Abstract

A series of starburst oligomers (T1-T3) that contained a fully diarylmethene-bridged triphenylamine core and oligofluorene arms were designed and synthesized through Suzuki cross-coupling reactions. Their thermal, photophysical, and electrochemical properties were also investigated. These materials showed high glass transition, in the range of 123-129 °C, and good film-forming abilities. They displayed deep-blue emission both in solution and as thin films. Solution-processed devices based on these oligomers exhibited highly efficient deep-blue electroluminescence and the device performances were significantly enhanced with the extension of the oligofluorene arms. The double-layered device that contained T3 as an emitter showed a maximum current efficiency of 3.83 cd A(-1) and a maximum external quantum efficiency of 4.19% with CIE coordinates of (0.16, 0.09), which are among the highest values for undoped deep-blue OLEDs that are based on solution-processable starburst oligomers.

Cyano‐Functionalized Triarylamines on Au(111): Competing Intermolecular versus Molecule/Substrate Interactions

“…These planarized triarylamines, so‐called heterotriangulenes, are currently experiencing a vigorous renaissance as versatile building blocks for functional optoelectronic materials . In particular, various derivatives of dimethylmethylene‐bridged triarylamines were shown to act as promising hole conductors with superior stability in light‐emitting devices or as efficient chromophores for dye‐sensitized solar cells…”

Highly Efficient, Simplified, Solution‐Processed Thermally Activated Delayed‐Fluorescence Organic Light‐Emitting Diodes

“…Finally, we fabricated solution‐processed TADF blue‐emitting OLEDs using 1,2‐bis(carbazol‐9‐yl)‐4,5‐dicyanobenzene (2CzPN) as a blue‐emitting dopant and 1,3‐bis(9H‐carbazol‐9‐yl)‐benzene (mCP) as a host (Figure c,d, inset); to the best of our knowledge, this is the first such device. These blue‐emitting solution‐processed OLEDs showed higher device efficiencies (EQE ≈ 8.1%, CE ≈ 14 cd A −1 , PE ≈ 8.6 lm W −1 ) than conventional fluorescence blue‐emitting OLEDs (Figure c,d and Figure S5c, Supporting Information) …”

Sports Psychological Measurement And Statistical Method from the Perspective of Sports Public Service

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