Seebeck coefficient controlled by magnetic field based on the P3HT/PCBM heterojunction device

Abstract

Abstract In this article, Magneto-Seebeck effect was studied by applying P3HT/PCBM bulk heterojunction devices. We found that illumination and magnetic field can improve the Seebeck coefficient of the pure P3HT device. Our magneto-photocurrent (MPC) effects indicate that the singlet and triplet ratios in these devices can be changed by external magnetic field. Furthermore, the Seebeck coefficient under light was measured as changing temperature and magnetic field. Based on the experimental results and theoretical models, we conclude that the change of singlet and triplet ratios caused by magnetic field influences carrier concentration, and affects the thermoelectric properties of organic semiconductor materials and devices. In addition, the impact of magnetic fields on Seebeck coefficient in our experiments differs from the traditional magnetic field effects, which becomes more conspicuous as temperatures rises at high temperature. Our study can further develop magnetic-thermoelectric effects, and contribute to presenting new strategies about magnetic-photo-thermoelectric coupling.