Tuning of multifunctional Cu-doped ZnO films and nanowires for enhanced piezo/ferroelectric-like and gas/photoresponse properties.

The prospect of tuning and enhancing multiple properties of ZnO from optical, electrical, piezo to ferroelectricity/magnetism with Cu dopants will certainly spur the pursuit of facile doping methodology to immensely advance this field of research. Here, a one-step aqueous synthesis of Cu-doped ZnO nanostructured materials with effective controllability over the morphology (film to nanowire) and doping concentrations both on rigid and flexible substrates has been developed. High structural integrity Cu-doped ZnO films and nanowires were achieved without multiple/harsh post-processing which tends to degrade their functional properties. Comprehensive investigations of varying doping concentrations on the enhancement and tunability of room temperature piezo/ferroelectricity to gas/photosensing multifunctional properties were systematically reported for the first time.