Optically Controlled Magnetization and Magnetoelectric Effect in Organic Multiferroic Heterojunction

The organic multiferroic effect receives increasing attention in organic electronics. Recently, the renaissance of organic multiferroics has yielded in a deep understanding of organic magnetism and magnetoelectric coupling. Here, through fabricating polythiophene nanowire/CH3NH3PbBr3 multiferroic heterojunction, the origin of organic magnetism, optically controlled magnetization, and magnetoelectric coupling with optical approach is studied. Specifically, the optical approach utilizes double beam 355 and 607 nm excitations to separately operate the CH3NH3PbBr3 and polythiophene nanowire layers. This double-beam-light approach allows to elucidate the effects of photogenerated charges on organic magnetism and magnetoelectric coupling effect. It is found that magnetization and magnetoelectric coupling of polythiophene nanowire/CH3NH3PbBr3 heterojunction can be effectively tuned through the photoexcitation of CH3NH3PbBr3, rather than photoexcitation of polythiophene nanowire phase, which has been further confirmed by electron spin resonance. Furthermore, the dominated factors are discussed to reveal room-temperature magnetization in organics. This work provides a strategy for optically controlled organic magnetism and magnetoelectric effect in charge transfer heterojunction.