A facile method to oxidize p-type Zinc Selenide nanowires into n-type Zinc Oxide nanowires

A facile method was used to oxidize p-type Zinc Selenide (ZnSe) nanowires into n-type Zinc Oxide (ZnO) through a 700 °C annealing process in air. Single crystal ZnSe nanowires, with a hole concentration of 0.805 × 10 18  cm −3 and a negative photoconductivity, were oxidized into polycrystalline ZnO nanowires with an electron concentration of 4.88 × 10 18  cm −3 and a positive photoconductivity. Additionally, both the as-synthesized ZnSe nanowires and the post-oxidized ZnO nanowires presented excellent optoelectronic properties. This method can be used to construct radial p–n junctions or other nano-devices based on a single NW through a regioselective oxidation process.