Heterojunction photodiodes based on honeycomb structures for ultraviolet detection

The p-NiO/n-ZnO heterojunction device based on honeycomb structures was fabricated by RF sputtering method. The structural and optical properties of the p-NiO/n-ZnO heterojunction were characterized by X-ray diffraction (XRD), UV-visible spectroscopy, field-emission scanning electron microscope (FE-SEM), and current-voltage (I-V) photocurrent measurements. The XRD spectra indicate that ZnO films were of hexagonal wurtzite structures, preferentially (002) oriented. SEM show that the spherical polystyrene stacking on hexagonal close-packing lattice structure. Optical measurements showed that the honeycomb structures exhibited the maximum haze values up to 50% at wavelength range 380-800 nm. The I-V curve of the heterojunction demonstrates obvious rectifying diode behavior in a dark environment. The lowest of leakage current is 8:23 × 10 ^-9 A/cm ² for p-NiO/n-ZnO heterojunction device.