Growth of nanostructured CuO thin films via microplasma-assisted, reactive chemical vapor deposition at high pressures

A variety of nanostructured CuO thin films composed of vertically-aligned wires, needles, leaves, trees, and fans were grown using DC microplasma jets at high pressure (∼10 Torr) under oxidizing conditions. A directed flux of active Cu species (atoms, metastables, etc.) for growth was created through dissociation of an organometallic Cu precursor in the hollow-cathode region of a flow-stabilized microplasma, followed by entrainment of species in the expanding, supersonic gas jet. Phase-pure CuO films were spray-deposited onto Si and ITO using both static and raster-scanned jet configurations with growth rates as high as several nm/s. The effects of background gas atmosphere, precursor flux, deposition time, substrate scanning speed, and substrate temperature on CuO film morphology and growth rate are discussed.

► Vertically-aligned CuO nanowires were grown via microplasma-assisted CVD. ► Organometallic precursors were dissociated in a hollow cathode, supersonic plasma jet. ► Nanostructured CuO films were spray-deposited on Si and ITO substrates at low T. ► CuO growth rates approached several nm/s. ► Gas atmosphere, flux, jet scanning, and T effects on film morphology were studied.