Rectifying behavior of electrically aligned ZnO nanorods

We report on the electrical alignment of ZnO nanorods and their electrical properties. The ZnO nanorods were wet-chemically synthesized, and their length and diameter were adjusted to about 200-300 nm and 15-30 nm, respectively. The nanorods were deposited onto electrode structures and directed into 200- to 800-nm-wide electrode gaps by using alternating electric fields at frequencies between 1 and 10 kHz and field strengths between 10(6) and 10(7) V/m. The nanorods align parallel to the electric field lines and make electrical contact with the gold electrodes. Clear photoresponse to 366-nm ultraviolet light irradiation was demonstrated. The current-voltage characteristics of the aligned rods are strongly nonlinear and asymmetrical, showing rectifying, diode-like behavior and asymmetry factors up to 25 at 3-V bias voltage.