Amb motiu del tancament d'estiu, la validació de documents es reprendrà a partir del 28 d'agost de 2026. Disculpeu les molèsties.
Con motivo del cierre de verano, la validación de documentos se reanudará a partir del 28 de agosto de 2026. Disculpad las molestias
Due to the summer closure, document validation will resume starting August 28, 2026. We apologize for any inconvenience.

Document type

Article

Version

Accepted version

Publication date

All rights reserved

Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/159774

Singlet-to-triplet interconversion using hyperfine as well as ferromagnetic fringe fields

Journal Title

Director/Tutor

Journal ISSN

Volume Title

Abstract

Until recently the important role that spin-physics ('spintronics') plays in organic light-emitting devices and photovoltaic cells was not sufficiently recognized. This attitude has begun to change. We review our recent work that shows that spatially rapidly varying local magnetic fields that may be present in the organic layer dramatically affect electronic transport properties and electroluminescence efficiency. Competition between spin-dynamics due to these spatially varying fields and an applied, spatially homogeneous magnetic field leads to large magnetoresistance, even at room temperature where the thermodynamic influences of the resulting nuclear and electronic Zeeman splittings are negligible. Spatially rapidly varying local magnetic fields are naturally present in many organic materials in the form of nuclear hyperfine fields, but we will also review a second method of controlling the electrical conductivity/electroluminescence, using the spatially varying magnetic fringe fields of a magnetically unsaturated ferromagnet. Fringe-field magnetoresistance has a magnitude of several per cent and is hysteretic and anisotropic. This new method of control is sensitive to even remanent magnetic states, leading to different conductivity/electroluminescence values in the absence of an applied field. We briefly review a model based on fringe-field-induced polaronpair spin-dynamics that successfully describes several key features of the experimental fringe-field magnetoresistance and magnetoelectroluminescence.

Citation

Citation

WOHLGENANNT, M., et al. Singlet-to-triplet interconversion using hyperfine as well as ferromagnetic fringe fields. Philosophical Transactions of the Royal Society A: Mathematical. Physical and Engineering Sciences. Vol.  2015, num. 373, pags. 20140326. ISSN 1364-503X. [consulted: 13 of August of 2026]. Available at: https://hdl.handle.net/2445/159774

Export metadata

JSON - METS

Share record