PtIr/ZnO nanowire/pentacene hybrid back-to-back double diodes

We report the PtIr/ ZnO nanowire/pentacene hybrid double diodes which are composed of the back-to-back Schottky and p-n junction diodes. The electric transport is dominated by both the Schottky barrier and the hybrid p-n junction. The diodes exhibit a low OFF current of 2 x 10(-3) nA between +/- 1.1 V. The negative differential resistance (NDR) is observed when the applied voltage is sweeping from negative to positive or from positive to negative values at room temperature. The origin of the NDR is suggested to be attributed to the presence of the air-gap dielectric between the ZnO nanowire and the pentacene film. (C) 2008 American Institute of Physics.