Improving solar control of magnetism in ternary organic photovoltaic system with enhanced photo-induced electrons doping

The growing demand for storage space has promoted in-depth research on magnetic performance regulation in an energy-saving way. Recently, we developed a solar control of magnetism, allowing the magnetic moment to be manipulated by sunlight instead of the magnetic field, current, or laser. Here, binary and ternary photoactive systems with different photon-to-electron conversions are proposed. The photovoltaic/magnetic heterostructures with a ternary system induce larger magnetic changes due to higher short current density (J_SC) (20.92 mA·cm⁻²) compared with the binary system (11.94 mA·cm⁻²). During the sunlight illumination, ferromagnetic resonance (FMR) shift increases by 80% (from 169.52 to 305.48 Oe) attributed to enhanced photo-induced electrons doping, and the variation of saturation magnetization (M_S) is also amplified by 14% (from 9.9% to 11.3%). Furthermore, photovoltaic performance analysis and the transient absorption (TA) spectra indicate that the current density plays a major role in visible light manipulating magnetism. These findings clarify the laws of sunlight control of magnetism and lay the foundation for the next generation solar-driven magneto-optical memory applications.