Jian-Hong Lee

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/cm2 for p-NiO/n-ZnO heterojunction device.