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 (E 2 (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.