Enhancement of organic magnetoresistance by electrical conditioning

We demonstrate that electrical conditioning can be used as an efficient method to enhance the organic magnetoresistance effect in organic light emitting diodes. Depending on duration and intensity of the conditioning process the absolute value of the magnetoresistance effect can be increased from ∼1% to values exceeding 15% at 40mT in devices based on poly(paraphenylene vinylene). Qualitatively, the increase in magnetoresistance can be correlated with a decrease in luminance during the conditioning process. From this we conclude that device degradation mechanisms are responsible for the enhancement of organic magnetoresistance.