We have performed magnetoresistance measurements on polyfluorene sandwich devices in weak magnetic fields as a function of applied voltage, device temperature (10K to 300K), film thickness and electrode materials. We observed either negative or positive magnetoresistance, dependent mostly on the applied voltage, with a typical magnitude of several percent. The shape of the magnetoresistance curve is characteristic of weak localization and antilocalization. Using weak localization theory, we find that the phase-breaking length is relatively large even at room temperature, and spin-orbit interaction is a function of the applied electric field.
@article{arxiv.cond-mat/0312204,
title = {Weak localization and antilocalization in semiconducting polymer sandwich devices},
author = {Ö. Mermer and M. Wohlgenannt and G. Veeraraghavan and T. L. Francis},
journal= {arXiv preprint arXiv:cond-mat/0312204},
year = {2016}
}