Growth of AZO/Cu/AZO multilayer structures by confocal RF magnetron sputtering and their microstructural and optoelectronic properties before and after annealing

•AZO/Cu/AZO multilayer films were grown on glass substrates by confocal RF sputtering.•Film orientation and crystallite sizes are affected by heat treatment.•Average transmittance depends on Cu thickness and annealing temperature.•PL spectra show that the emission of all films is dominated by a sharp UV band.•Figures of merit of as-deposited structures are better than those of annealed ones.