title: Positive temperature coefficient of resistance of single ZnO nanorods.
abstract: ZnO nanorods were synthesized by a simple aqueous solution method. Crystal structures and morphology studies show that the ZnO nanorods are single crystalline with the growth direction aligned with the c axis of ZnO. An Au-ZnO nanorod-Au (metal-semiconductor-metal, MSM) device using the synthesized nanorod was fabricated. An electronic model with two back-to-back Schottky diodes in series with a nanorod was used to describe the electrical transport of the MSM device. A positive temperature coefficient of resistance is observed on a single ZnO nanorod from 383 to 473 K. A simple model has been proposed to explain such an abnormal behavior including the effect of the interface states and the adsorption-desorption of the water/oxygen molecules on the surface of the nanorod.
authors.affiliation: School of Physics and Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Guan-nan
authors.initials: GN
authors.lastname: He
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.forename: Hui
authors.initials: H
authors.lastname: Shen