Large room-temperature magnetoresistance in lateral organic spin valves fabricated by in situ shadow evaporation

• We demonstrate a lateral organic spin valve.
• Channel length of the spin valve is less than 100 nm.
• Fabrication of the devices is done by a new shadow evaporation process.
• 50% Magnetoresistance with hysteretic behavior is observed at room temperature.
• Strong indication of lateral tunneling visible in the devices’ behavior.

We report the successful fabrication of lateral organic spin valves with a channel length in the sub 100 nm regime. The fabrication process is based on in situ shadow evaporation under UHV conditions and therefore yields clean and oxygen-free interfaces between the ferromagnetic metallic electrodes and the organic semiconductor. The spin valve devices consist of Nickel and Cobalt–Iron electrodes and the high mobility n-type organic semiconductor N,N′-bis(heptafluorobutyl)-3,4:9,10-perylene diimide. Our studies comprise fundamental investigations of the process’ and materials’ suitability for the fabrication of lateral spin valve devices as well as magnetotransport measurements at room temperature. The best devices exhibit a magnetoresistance of up to 50%, the largest value for room temperature reported so far.

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