Sk, B and Ravindran, E and Deori, U and Yadav, N and Nanda, GP and Rajamalli, P (2022) A deep blue thermally activated delayed fluorescence emitter: balance between charge transfer and color purity. In: Journal of Materials Chemistry C, 10 (12). pp. 4886-4893.
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Abstract
An efficient blue organic light-emitting diode (OLED) device with high color purity is a challenging issue with technological relevance. Herein, we demonstrated the role of the donor substitution position in a thermally activated delayed fluorescence (TADF) emitter to achieve deep blue emission with improved color purity without reducing the device performance. A novel (4-(3,6-di-tert-butyl-9H-carbazol-9-yl)phenyl)(6-(3,6-di-tert-butyl-9H-carbazol-9-yl)pyridin-3-yl)methanone (3BPy-pDTC) was synthesized, where two tert-butyl carbazolyl (DTC) donors linearly connected at the para position of the benzoyl pyridine (3BPy) acceptor core. The 3BPy-pDTC emitter shows a low �EST value of 0.19 eV with a subsequent overlap between holes and electrons which leads to a high photoluminescence quantum yield (PLQY) of 93. Besides, this emitter exhibits narrow emission spectra with a full-width at half maximum (FWHM) of 58 nm. The OLED device using the 3BPy-pDTC dopant provided a high external quantum efficiency (EQE) of 25 with deep blue emission at λmax of 458 nm. 3BPy-pDTC shows color purity in deep blue emission as compared to its meta substituted counterpart (3BPy-mDTC) due to the locked geometry via intramolecular H-bonding and weak excited state charge transfer (CT) interactions. The current study paves the way for developing deep-blue TADF emitters with high efficiency and color purity. © 2022 The Royal Society of Chemistry
| Item Type: | Journal Article |
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| Publication: | Journal of Materials Chemistry C |
| Publisher: | Royal Society of Chemistry |
| Additional Information: | The copyright for this article belongs to authors. |
| Keywords: | Charge transfer; Color; Efficiency; Emission spectroscopy; Excited states; Fluorescence; Organic light emitting diodes (OLED); Quantum efficiency; Synthesis (chemical), Blue organic light emitting diodes; Carbazol; Carbazolyl; Color purity; Deep blue; Deep-blue emissions; Device performance; Methanone; Synthesised; Thermally activated delayed fluorescences, Supercomputers |
| Department/Centre: | Division of Chemical Sciences > Materials Research Centre |
| Date Deposited: | 18 May 2022 05:54 |
| Last Modified: | 18 May 2022 05:54 |
| URI: | https://eprints.iisc.ac.in/id/eprint/71808 |
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