Fig. 1

Schematic of the fabrication process steps to synthesize vertically aligned ZnO NR arrays. a A substrate coated with a ZnO NP seed layer, a polymer resist layer and PS-NBs. b Thermal evaporation of an Al mask. c Removing the Al-coated PS-NBs by tape stripping. d Dry etching of the resist. e Wet etching of the Al mask. f Selective ZnO NR growth in the holes of the patterned resist template