Magnetoconductance responses of triplet polaron pair charge reaction in hyperfine coupling regime

This study investigates a distinct low-field negative magnetoconductance (MC) response under illumination in pentacene:fullerene heterojunction devices. The low-field negative MC response is attributed to a triplet polaron pair ((PP)(3)) charge reaction associated with the hyperfine interaction. Applying a magnetic field can reduce the intensity of the reaction causing the negative MC response. Additionally, the low-field negative MC response changes with the blending ratios of fullerene in pentacene active layer, the applied bias voltages, and applying device structure with bulk heterojunction or planar heterojunction configuration, because the modulations of the internal electric field. Consequently, the results indicate that the (PP)(3) charge reaction induces the low-field negative MC, which is correlated with the local hyperfine field, external magnetic field, and electric field. (C) 2013 AIP Publishing LLC.