Fabrication and Characterization of Ni-Doped ZnO Nanorod Arrays for UV Photodetector Application

In this work, the structure morphologies, lattices, and optical properties of zinc oxide (ZnO) nanorods (NRs) with various amounts of nickel (Ni) dopants were investigated and explored. The 100 nm ZnO seed layer was grown on the Corning glass substrate by the radio frequency (RF) magnetron sputtering technique, and the chemical bath deposition (CBD) method was used to grow NR arrays. It was found that the Ni concentration of the sample is 1.06 at% by EDX spectra examination. All the NRs exhibited a hexagonal wurtzite structure and preferentially grew along the c-axis on the substrate. Additionally, the ultraviolet (UV) photodetectors (PDs) with Ni-doped ZnO (NZO) NRs based on metal-semiconductor-metal (MSM) structure were fabricated through a photolithography process. Then, such a sample was annealed at 500 °C to obtain good performance and reduced oxygen vacancy (∼560 nm). The results showed that the NZO NRs were with an excellent photosensitivity for UV PD applications and a faster rise/decay time than pure ZnO. Furthermore, with a 3 V applied bias and 380 nm UV illumination, the sensitivities of the fabricated ZnO PDs with different Ni contents (0, 4, and 8 mM) were 71.45, 393.04, and 238.75, respectively.