Photoelectron-induced quantitative regulation of ferromagnetism in Permalloy at room temperature for photovoltaic flexible spintronics

Flexible spintronics has recently sparked an upsurge due to the growing demand for miniaturization, high-speed, integration and energy-saving in portable and wearable devices. However, the stress/strain during the substrate deformation process is inevitable for flexible spintronic devices and may be available to assist the switching of the magnetization, accordingly. Therefore, combined with the previously discovered high energy efficient sunlight controlled magnetization switching, we propose a bending-insensitive photovoltaic flexible spintronic device constructed by PET/Ta/Permalloy/(PC71BM: PTB7-Th)/Pt heterostructure. The bent device achieved a 281 Oe of maximal ferromagnetic resonance (FMR) field shift by photoelectrons in a reversible manner under the sunlight soaking at room temperature. And the magnetic change as a function of the external light radiation was precisely determined. These findings provide a feasible way to combine the flexible substrate and photoelectrons for energy-saving and precise manipulation of magnetism in bendable spintronic devices. [Display omitted] •The stress/strain during the substrate deformation process is inevitable for flexible spintronic devices.•A bending-insensitive photovoltaic flexible spintronic device is developed.•The bent device achieved a reversible 281 Oe ferromagnetic resonance field shift by photoelectrons at room temperature.•These findings provide a way for energy-saving and precise manipulation of magnetism in bendable spintronic devices.