Transparent nanostructured electrodes: Electrospun NiO nanofibers/NiO films

• Nanostructured electrodes: electrospun NiO nanofibers/NiO films were fabricated.
• NiO fibers were directly grown on insulating substrate coated by thin Ni or NiO films.
• Good quality crystalline fibers were obtained at low calcination temperatures.
• Transparent and conductive p-type electrodes were fabricated.

Polyvinylpyrrolidone (PVP)/nickel(II) acetate precursor fibers were deposited by electrospinning directly on radio frequency sputtered thin Ni and NiO films grown on quartz substrate, starting from Ni(II) acetate and PVP solution in ethanol. The samples were calcined in air in the temperature range 400–500 °C to obtain transparent and conductive p-type NiO nanofibers on NiO films. A higher density of nanofibers was obtained on Ni/quartz substrates, as compared to NiO/quartz ones, demonstrating the feasibility of fiber adhesion directly to an insulating substrate previously coated by a thin Ni layer.Samples were characterized by field emission-scanning electron microscopy, X-ray diffraction, spectrophotometric and resistance measurements.