Sharif, Parisa and Alemdar, Eda and Ozturk, Soner and Caylan, Omer and Haciefendioglu, Tugba and Buke, Goknur and Aydemir, Murat and Danos, Andrew and Monkman, Andrew P. and Yildirim, Erol and Gunbas, Gorkem and Cirpan, Ali and Oral, Ahmet (2022) 'Rational Molecular Design Enables Efficient Blue TADF−OLEDs with Flexible Graphene Substrate.', Advanced Functional Materials, 32 (47). p. 2207324.
Abstract
Observation of thermally activated delayed fluorescence (TADF) in conjugated systems redefined the molecular design approach to realize highly efficient organic light emitting diodes (OLEDs) in the early 2010s. Enabling effective reverse intersystem crossing (RISC) by minimizing the difference between singlet and triplet excited state energies (ΔEST) is proven to be a widely applicable and fruitful approach, which results in remarkable external quantum efficiencies (EQE). The efficacy of RISC in these systems is mainly dictated by the first-order mixing coefficient (λ), which is proportional to spin-orbit coupling (HSO) and inversely proportional to ΔEST. While minimizing ΔEST has been the focus of the OLED community over the last decade, the effect of HSO in these systems is largely overlooked. Here, molecular systems with increased HSO are designed and synthesized by substituting selected heteroatoms of high-performance TADF materials with heavy-atom selenium. A new series of multicolor TADF materials with remarkable EQEs are achieved. One of these materials, SeDF-B, results in pure blue emission with EQEs approaching 20%. Additionally, flexible graphene-based electrodes are developed for OLEDs and revealed to have similar performance as standard indium tin oxide (ITO) in most cases. These devices are the first report of TADF based OLEDs that utilize graphene-based anodes.
| Item Type: | Article |
|---|---|
| Full text: | Publisher-imposed embargo until 22 September 2023. (AM) Accepted Manuscript File format - PDF (1429Kb) |
| Status: | Peer-reviewed |
| Publisher Web site: | https://doi.org/10.1002/adfm.202207324 |
| Publisher statement: | This is the peer reviewed version of the following article: Sharif, Parisa, Alemdar, Eda, Ozturk, Soner, Caylan, Omer, Haciefendioglu, Tugba, Buke, Goknur, Aydemir, Murat, Danos, Andrew, Monkman, Andrew P., Yildirim, Erol, Gunbas, Gorkem, Cirpan, Ali & Oral, Ahmet (2022). Rational Molecular Design Enables Efficient Blue TADF−OLEDs with Flexible Graphene Substrate. Advanced Functional Materials 32(47): 2207324., which has been published in final form at https://doi.org/10.1002/adfm.202207324. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. |
| Date accepted: | No date available |
| Date deposited: | 07 December 2022 |
| Date of first online publication: | 22 September 2022 |
| Date first made open access: | 22 September 2023 |
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