Abstract

Zinc oxide is one of the wide band gap semiconductors. By using the ZnO-layer as an active channel layer, transparent transistors (ZnO-TFTs) have been constructed. The ratio Ion/Ioff of ZnO-TFTs fabricated on Si-wafers is about 106 and the optical transmittance of ZnO-TFTs fabricated on glass is more than 80%. It is also performed that the magnetic properties of ZnO thin films are controlled by V or Co doping under the non-equilibrium condition. Ferromagnetic properties of Co-ZnO films are confirmed by not only SQUID but also MCD and core-level XAS. Relatively weak signal of ferromagnetics suggests that a part of the film shows ferromagnetic character due to the inhomogeneous of the doped exotic cations (V, Co etc.). These results show that it is possible to fabricate a transparent spin-FET that can be operated even in the presence of visible light