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 106 and 107 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.