Organic-inorganic hybrid spin valves with different organic spacers

A series of novel organic spin valve devices with a Fe3O4/Al-O/organic semiconductors (OSs)/Co/Al stacking structure was fabricated. Here, four kinds of OSs, Poly(vinylidene fluoride) (PVDF), rubrene, C60 and Alq3 were tested in the devices. The spin-dependent transport properties and magnetoresistance (MR) effect were systemically studied. Giant MR ratio over 8% was observed at 300 K in C60-based spin valves, which is one of the highest MR ratios reported so far. Moreover, a large SDT length of over 100 nm was experimentally observed in the C60 layer at room temperature. Tunneling MR ratio was achieved over 6% in rubrene and Alq3 based spin valves at room temperature. It is noted that the tunneling MR ratios at room temperature are around 2% for devices with 3 layers of PVDF. The relations between OSs spacer and MR effect were discussed.