On the properties of ZnO nanorods (ZnO NRs)/NiO heterostructure prepared by double chemical bath deposition

Abstract

We report on the ZnONRs and ZnONRs/NiO heterostructure synthesized by the chemical bath deposition technique. The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy, Raman spectroscopy, and UV-VIS spectroscopy techniques. XRD, Raman spectroscopy, and SEM analysis revealed the formation of ZnONRs/NiO heterostructure. Raman spectra showed a decrease in intensity of low-frequency non-polar and active (E2 (low)) vibrational mode when NiO is deposited onto ZnONRs. The PL spectra revealed ultraviolet and visible emission bands, whose intensities decreased when NiO grew onto ZnONRs. The Au/NiO/ZnONRs/FTO heterostructure Schottky diode performed better than the Au/ZnONRs/FTO Schottky diode. The Au/NiO/ZnONRs/FTO heterojunction demonstrated a current rectification ratio of 3.03 × 102 at ±2 V and a forward current of 1.51 × 10-3 A, which is higher than that of Au/ZnONRs/FTO having a rectification ratio of 6.79 × 101 at ±2 V and a forward current of 1.651 × 10-5 A.