Organic field-effect transistors for spin-polarized transport

In order to combine the merits of the rapidly developing fields of spintronics and organic electronics, we present a concept of an organic field-effect transistor (OFET) for spin-polarized transport, enabling a non-volatile activation and deactivation by magnetic field pulses. This new steering parameter in addition to the usual steering by the electrical gate voltage opens the path toward programmable logics. In our concept, the magnetic-field sensitivity is achieved by the employment of ferromagnetic source and drain contacts with different coercive field strength. This enables a separate switching of its magnetization directions. The resulting parallel or anti-parallel orientation of the magnetization of source and drain corresponds to a low or high channel resistance for the spin-polarized electrons. On the route towards the experimental realization of this device, we present a working OFET, based on dihexylquaterthiophene (DH4T), with ferromagnetic FeCoB stripes as source and drain contacts. Besides, the ability of a separate switching of the contact stripe magnetizations is demonstrated. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.