Solar manipulations of perpendicular magnetic anisotropy for flexible spintronics

Flexible electronics/spintronics attracts researchers’ attention for their application potential abroad in wearable devices, healthcare, and other areas. Those devices’ performance (speed, energy consumption) is highly dependent on manipulating information bits (spin-orientation in flexible spintronics). In this work, we established an organic photovoltaic (OPV)/ ZnO/Pt/Co/Pt heterostructure on flexible PET substrates with perpendicular magnetic anisotropy (PMA). Under sunlight illumination, the photo-electrons generated from the OPV layer transfer into the PMA heterostructure, then they reduce the PMA strength by enhancing the interfacial Rashba field accordingly. The coercive field (H_c) reduces from 800 Oe to 500 Oe at its maximum, and the magnetization can be switched up and down reversibly. The stability of sunlight control of magnetization reversal under various bending conditions is also tested for flexible spintronic applications. Lastly, the voltage output of sunlight-driven PMA is achieved in our prototype device, exhibiting an excellent angular dependence and opening a door towards solar-driven flexible spintronics with much lower energy consumption.