Selective growth of zinc oxide nanorods on inkjet printed seed patterns

A method for the selective patterning of zinc oxide (ZnO) nanorods is presented that combines inkjet printing of zinc acetate precursors on a substrate used to form ZnO nanocrystallites that subsequently grow into nanorods in a reaction bath containing zinc acetate and hexamethylamine during a hydrothermal process. A total of 100 μm patterns were formed on glass substrates kept at fixed temperatures by printing dots that can also form lines, arrays and rectangular patterns through the use of a 50 μm printhead. Different concentrations of zinc acetate (0.1–1 M) ink-jetted onto the substrates led to the growth of 100 nm to 1 μm wide ZnO nanorods vertically out of the substrates. The length of the ZnO nanorods could be controlled by the concentration of the precursor solution during the hydrothermal process as well as the duration of growth process.