Emissive Material Optimization for Solution-Processed Exciplex OLEDs
| Autor: | Tanja Leitner, Paul E. Shaw, Almantas Pivrikas, Paul L. Burn, Ian R. Gentle, Jaber Saghaei, Van T. N. Mai, Chandana Sampath Kumara Ranasinghe |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Photoluminescence Materials science Oxadiazole Quantum yield 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry Triphenylamine 01 natural sciences Acceptor 0104 chemical sciences Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Materials Chemistry Electrochemistry OLED Quantum efficiency 0210 nano-technology Alkyl |
| Zdroj: | ACS Applied Electronic Materials. 3:4757-4767 |
| ISSN: | 2637-6113 |
| DOI: | 10.1021/acsaelm.1c00630 |
| Popis: | Exciplex or charge transfer blends can be emissive in a similar manner to thermally activated delayed fluorescent materials but without the requirement for covalent linkages. Exciplex blends have been mainly used in organic light-emitting diodes fabricated using thermal evaporation, which is in part due to the poor film forming properties of evaporable materials when processed from solution. In this paper, we report the synthesis of three oxadiazole derivatives designed to have good solubility and compare the properties with commercial 1,3-bis[2-(4-t-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene (OXD-7). The acceptor materials have 4-(2-ethylhexyloxy)phenyl or 9,9-di-n-alkylfluoren-2-yl (where the alkyl groups are either n-propyl or n-hexyl) end groups as opposed to the 4-t-butylphenyl moieties of OXD-7. Neat films of the synthesized oxadiazole derivatives were found to have electron mobilities an order of magnitude higher than that of OXD-7. The oxadiazole derivatives were found to be miscible with the hole transporting 4,4′,4″-tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA) with charge transfer emission from solution-processed films. The 4-(2-ethylhexyloxy)phenyl-oxadiazole derivative exhibited the best overall performance when blended with m-MTDATA, with the solution-processed films having a photoluminescence quantum yield of around 21 ± 3% and simple bilayer OLEDs having a maximum external quantum efficiency of 5.3 ± 0.3%. |
| Databáze: | OpenAIRE |
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