Photovoltaic Tunable AMR Sensor

In this paper, a photovoltaic AMR sensor (PET/Ta (3 nm)/NiFe (d nm)/ PTB7-Th:PC71BM (80 nm)/Pt (3 nm)) is investigated. The device achieved maximal 364 Oe ferromagnetic resonance field shift and 402 Oe magnetic anisotropy field change under simulated sunlight. Significantly, the sensor achieved a 3-4 Ω magnetoresistance increase and a 36.8 % AMR ratio rise by sunlight illumination. And the increase of NiFe thin film thickness decreased the variation of AMR ratio. Excellent reversibility and reproducibility have also been exhibited. The doped photoelectrons can decrease the magnetic moment of NiFe and enhance the magnetoresistance by occupying 3d orbitals. The results demonstrate a promising application possibility in AMR sensors for photovoltaic spintronic devices in the future.