Milster, Sebastian and Gruenbaum, Tobias and Bange, Sebastian and Kurrmann, Simon and Kraus, Hermann and Stoltzfus, Dani M. and Leung, Anna E. and Darwish, Tamim A. and Burn, Paul L. and Boehme, Christoph and Lupton, John M. (2020) Perdeuterated Conjugated Polymers for Ultralow-Frequency Magnetic Resonance of OLEDs. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 59 (24). pp. 9388-9392. ISSN 1433-7851, 1521-3773
Full text not available from this repository. (Request a copy)Abstract
The formation of excitons in OLEDs is spin dependent and can be controlled by electron-paramagnetic resonance, affecting device resistance and electroluminescence yield. We explore electrically detected magnetic resonance in the regime of very low magnetic fields (<1 mT). A pronounced feature emerges at zero field in addition to the conventional spin-1/2Zeeman resonance for which the Larmor frequency matches that of the incident radiation. By comparing a conventional pi-conjugated polymer as the active material to a perdeuterated analogue, we demonstrate the interplay between the zero-field feature and local hyperfine fields. The zero-field peak results from a quasistatic magnetic-field effect of the RF radiation for periods comparable to the carrier-pair lifetime. Zeeman resonances are resolved down to 3.2 MHz, approximately twice the Larmor frequency of an electron in Earth's field. However, since reducing hyperfine fields sharpens the Zeeman peak at the cost of an increased zero-field peak, we suggest that this result may constitute a fundamental low-field limit of magnetic resonance in carrier-pair-based systems. OLEDs offer an alternative solid-state platform to investigate the radical-pair mechanism of magnetic-field effects in photochemical reactions, allowing models of biological magnetoreception to be tested by measuring spin decoherence directly in the time domain by pulsed experiments.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | RADICAL-PAIR MECHANISM; CHEMICAL COMPASS; MAGNETORECEPTION; MODEL; SPINS; conjugated polymers; deuteration; isotopes; magnetic resonance; organic light-emitting diodes |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Lupton > Group John Lupton |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 22 Mar 2021 07:17 |
| Last Modified: | 22 Mar 2021 07:17 |
| URI: | https://pred.uni-regensburg.de/id/eprint/44409 |
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