Effect of increasing electron donor units for high-efficiency blue thermally activated delayed fluorescence
| Autor: | Myoung-Seon Gong, Jae-Ryung Cha, Chil Won Lee |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Materials science Photoluminescence Process Chemistry and Technology General Chemical Engineering Exciton Electron donor 02 engineering and technology Electron acceptor 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Fluorescence 0104 chemical sciences chemistry.chemical_compound chemistry Intramolecular force OLED Quantum efficiency 0210 nano-technology |
| Zdroj: | Dyes and Pigments. 140:399-406 |
| ISSN: | 0143-7208 |
| DOI: | 10.1016/j.dyepig.2017.01.053 |
| Popis: | To enhance the efficiency of organic light-emitting diodes (OLEDs), the application of triplet excitons must be maximized. Two donor–acceptor-type molecules bearing bis-carbazolyl and tris-carbazolyl groups at the ortho position of a phenyl-attached triazine ring were synthesized. These molecules showed very small singlet–triplet energy gaps (ΔE ST ) of 0.06 and 0.03 eV, respectively, and transient photoluminescence (PL) characteristics, which indicate that they are thermally activated delayed fluorescence (TADF) materials. A high external quantum efficiency (EQE) of 16.5% with deep blue color coordinates of (0.15, 0.22) was observed using a TrisCz–Trz TADF emitter. This interaction between the electron donor and electron acceptor substituents plays a key role in achieving a very small ΔE ST and good intramolecular charge transfer (ICT) activities with high photoluminescence (PL). |
| Databáze: | OpenAIRE |
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