Nanosized perpendicular organic spin-valves

A fabrication process for perpendicular organic spin-valve devices based on the organic semiconductor Alq3 has been developed which offers the possibility to achieve active device areas of less than 500 × 500 nm2 and is flexible in terms of material choice for the active layers. Characterization of the resulting devices shows a large magnetoresistance of sometimes more than 100%, however with equally large variation from device to device. Comparison with large area spin-valves indicates that the magnetoresistance of both large and small devices most likely originates from tunneling through pinholes and tunneling magnetoresistance.