Abstract
Quantifying the spin-spin interactions which influence electronic transitions in organic semiconductors is crucial for understanding their magneto-optoelectronic properties. By combining a theoretical model for three spin interactions in the coherent regime with pulsed electrically detected magnetic resonance experiments on -conjugated polymer diodes (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]), we quantify the spin coupling within complexes comprising three spin-1/2 particles. We determine that these particles form triplet-exciton/polaron pairs, where the polaron-exciton exchange is over five orders of magnitude weaker ( MHz) than that within the exciton. This approach provides a direct spectroscopic approach for distinguishing between coupling regimes, and to test hypotheses relating microscopic properties to bulk characteristics of organic electronic devices.
- Received 4 February 2015
- Revised 13 April 2015
DOI:https://doi.org/10.1103/PhysRevB.92.041201
©2015 American Physical Society