Pyrenylpyridines: Sky-Blue Emitters for Organic Light-Emitting Diodes
| Autor: | Pratap K. Chhotaray, Boqian Yang, Thenahandi Prasanthi Deepthika De Silva, Frank R. Fronczek, Evgueni E. Nesterov, Isiah M. Warner, Sierra Sterling, Rashanique D. Quarels, Chun-Han Wang, Girija Sahasrabudhe, George G Tamas, Sang Gil Youm |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Photoluminescence
Materials science General Chemical Engineering Analytical chemistry 02 engineering and technology General Chemistry Electroluminescence 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 7. Clean energy Article 0104 chemical sciences Amorphous solid Chemistry Crystallinity chemistry.chemical_compound chemistry Pyridine OLED Quantum efficiency Thermal stability 0210 nano-technology QD1-999 |
| Zdroj: | ACS Omega ACS Omega, Vol 4, Iss 16, Pp 16867-16877 (2019) |
| ISSN: | 2470-1343 |
| Popis: | A novel sky-blue-emitting tripyrenylpyridine derivative, 2,4,6-tri(1-pyrenyl)pyridine (2,4,6-TPP), has been synthesized using a Suzuki coupling reaction and compared with three previously reported isomeric dipyrenylpyridine (DPP) analogues (2,4-di(1-pyrenyl)pyridine (2,4-DPP), 2,6-di(1-pyrenyl)pyridine (2,6-DPP), and 3,5-di(1-pyrenyl)pyridine (3,5-DPP)). As revealed by single-crystal X-ray analysis and computational simulations, all compounds possess highly twisted conformations in the solid state with interpyrene torsional angles of 42.3°-57.2°. These solid-state conformations and packing variations of pyrenylpyridines could be correlated to observed variations in physical characteristics such as photo/thermal stability and spectral properties, but showed only marginal influence on electrochemical properties. The novel derivative, 2,4,6-TPP, exhibited the lowest degree of crystallinity as revealed by powder X-ray diffraction analysis and formed amorphous thin films as verified using grazing-incidence wide-angle X-ray scattering. This compound also showed high thermal/photo stability relative to its disubstituted analogues (DPPs). Thus, a nondoped organic light-emitting diode (OLED) prototype was fabricated using 2,4,6-TPP as the emissive layer, which displayed a sky-blue electroluminescence with Commission Internationale de L'Eclairage (CIE) coordinates of (0.18, 0.34). This OLED prototype achieved a maximum external quantum efficiency of 6.0 ± 1.2% at 5 V. The relatively high efficiency for this simple-architecture device reflects a good balance of electron and hole transporting ability of 2,4,6-TPP along with efficient exciton formation in this material and indicates its promise as an emitting material for design of blue OLED devices. |
| Databáze: | OpenAIRE |
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