LAUSR

Abstract Organic magnetoresistance is tightly related to the carrier spin. To explain the dependence of organic magnetoresistance on the driving voltage, we firstly study the spin polarization of a carrier with different energy through the tight-binding model. Then with a spin related hopping mechanism, we obtain the dependence of the magnetoresistance on the carrier spin. It is found that a high energy carrier will have a weak spin polarization, which results in a small magnetoresistance. By supposing the injected carrier energy is proportional to the driving voltage, our theoretical calculation is well consistent to the experimental data.