In Situ Generation of Red-Emissive AIEgens from Commercial Sources for Nondoped OLEDs

Abstract

Luminescent materials with red emission are promising materials for optoelectronic devices and biological sciences. However, their synthesis is often complicated. In this work, we developed a facile approach to generating red-emissive luminogens with aggregation-induced emission (AIE) characteristics from commercially available reactants. The new compounds, abbreviated PN-BTZ-Cz and DP-BTZ-Cz, were prepared by coupling 4,7-dibromobenzo[ c ][1,2,5]thiadiazole with (1-naphehyl)phenylamine or diphenylamine followed by the reaction of the monobromo-substituted compounds with carbazole. Although all of the reactants were non-AIE-active, PN-BTZ-Cz and DP-BTZ-Cz showed AIE characteristics. This suggested that the AIE chromophores were generated in situ through the reactions. PN-BTZ-Cz and DP-BTZ-Cz were soluble in common organic solvents and showed red emission with high fluorescence quantum yields of 42.2 and 38.3% in the film, respectively. They were thermally and morphologically stable, as revealed by their high decomposition temperature (up to 327 °C) and glass-transition temperature (up to 120 °C). Nondoped organic light-emitting diodes with a configuration of ITO/HATCN/TAPC/PN-BTZ-Cz or DP-BTZ-Cz/Bphen/Liq/Al were fabricated using these compounds as emitting layers, which emitted red electroluminescence at a low turn-on voltage (down to 2.8 V) with a maximum external quantum yield of up to 2.7% and a small efficiency roll-off.

Albumin tailoring fluorescence and photothermal conversion effect of near-infrared-II fluorophore with aggregation-induced emission characteristics

“…Additionally, the emission spectrum was blue-shifted when water fraction was 80% or above (Fig. 1e) due to the AIE state 19,28 . This result evidenced that the fluorescence intensity of BPBBT was dominated by TICT state at a water fraction value below 30%, but the equilibrium was moved to AIE state when further raising the water fraction (Fig.…”

ICT and AIE Characteristics Two Cyano-Functionalized Probes and Their Photophysical Properties, DFT Calculations, Cytotoxicity, and Cell Imaging Applications

“…Further increasing the solvent polarities to high polar solvents (e.g., DMF and DMSO), the emission peak of AIE-2 further shifted to 488 nm (in DMF) and 494 nm (in DMSO) with a single prominent peak. It is known that on increasing the solvent polarities from low to high, the emission peak of a donor-acceptor moiety containing fluorophores shows a bathochromic shift with a decrease in the fluorescence intensity and quantum efficiency [56]. Thus, the change of emission of AIE-2 on increasing the solvent polarities was not unusual.…”

Restriction of Conformation Transformation in Excited State: An Aggregation-Induced Emission Building Block Based on Stable Exocyclic C=N Group

“…For TZPE, the aggregation process shows no significant effect on the intensity of the PL peaks. The slight PL drop as the f w increased may be ascribed to the aggregate size effect ( Yu et al., 2018a ; Jiang et al., 2017 ).…”