Enhanced performance of annealed NiO thin film for UV photodetection

This work presents the fabrication of Nickel oxide (NiO) Thin Film (TF) on a Si substrate through e-beam evaporation. The successful growth of the NiO TF was confirmed by field emission scanning electron microscopy analysis (thickness of ~ 375 nm for as-deposited and ~ 370 nm for annealed sample). Further, the as-deposited sample was then annealed at 400 °C in open-air conditions to investigate the improved structural and electrical properties. The X-ray diffraction analysis demonstrates the polycrystalline nature of both samples. The average crystallite size was increased from ~ 13.32 nm (as-deposited) to ~ 15.46 nm after annealing. Also, the electrical properties were examined using an Au electrode for both devices. Responsivity and detectivity values of 0.12 A/W and 3.28 × 1012 Jones, respectively, were obtained for as-deposited device, which was increased to 0.69 A/W and 10.54 × 1012 Jones, respectively, after annealing. Furthermore, the device exhibits a quick response time of 0.21 s (rise time) and 0.19 s (fall time) for as-deposited and 0.17 s (rise time) and 0.16 s (fall time) for annealed samples. These performance parameters observed in this fabricated device highlighted the suitability of NiO TF for photodetector applications.