Aligned ZnO Nanorods with Tunable Size and Field Emission on Native Si Substrate Achieved via Simple Electrodeposition

Large-scale arrays of aligned ZnO hexagonal nanorods with planar ends have been achieved on a bare native n -type (100) Si substrate via a simple electrochemical deposition in Zn(NH 3 ) 4 (NO 3 ) 2 solution with a pure Zn sheet as the anode without using any catalysts, additives, and additional seed crystals. The ZnO hexagonal nanorods grow from the single-crystal seeds self-formed in the initial stage of the electrochemical deposition. The diameters and the lengths of the ZnO nanorods can be tailored by adjusting the electrolyte concentration and the electrodeposition duration. Field-emission measurements show that the ZnO nanorods with smaller diameters exhibit lower turn-on field and higher current density. The well-aligned ZnO hexagonal nanorods (on Si substrate) with tunable size and field emission performance may have potentials in the future of nanotechnology.