Hydrothermal growth of ZnO nanorods aligned parallel to the substrate surface

Hydrothermal growth of ZnO nanorods with their c-axis aligned parallel to the surface of a Si (100) wafer substrate is demonstrated. With appropriate choice of process conditions (precursor concentrations, solution temperature, growth time), the (002) face of such nanorods is seen to support the emergence of as many as 10-20 aligned ZnO nanowires, with diameters of ∼50 nm and lengths that can extend to several micrometers. Similar growth of parallel nanorods/nanowires is observed on an amorphous carbon film surface. The influence of the substrate surface on the formation of such nanostructures is discussed. Such demonstrations of nanorod/nanowire growth parallel to a substrate surface could prove helpful in future nanodevice fabrication strategies.