Analysis of the core–shell interface between zinc-blende GaP and wurtzite ZnO

•Properties of interface between zinc-blende core and wurtzite shell were studied.•Radial PN is formed between the GaP core and ZnO shell during the deposition.•Individual nanowire processing used for preparation of nanowire diode.•Contribution from ZnO and GaP was identified in the spectral sensitivity curve.

Core–shell GaP/ZnO nanowires (NWs) were prepared in a two-step process: (1) GaP NWs were grown on GaP substrate by low-pressure metalorganic vapour phase epitaxy using 30 nm Au seeds as nucleation centres, (2) the GaP NWs were covered in a thin nanocrystalline Ga-doped ZnO layer by sputtering in a Perkin Elmer planar RF diode system. Electrical contacts were processed to individual GaP/ZnO NWs using electron beam lithography, evaporation and lift-off of metallic layers: Au/Zn (GaP core) and Au/Al (ZnO shell). Electrical and photocurrent measurement of the NWs confirmed that a radial pn heterojunction was formed between the GaP core and ZnO shell.