Enhanced structural, optical, and photo sensing properties of Ni-doped Co₃O₄ thin films prepared by nebulizer spray pyrolysis method

In the current manuscript, we deal with pure and 2, 4, 6, 8, and 10 wt% Ni-doped Co₃O₄ thin films prepared using the Nebulizer spray pyrolysis method. An in-depth discussion is provided on improving crystalline, morphological, optical, electrical, and photodetection characteristics of pure and Ni-doped samples. The cubic spinel structure of Co₃O₄ has been established by the X-ray diffraction (XRD) study. Microscopy studies using Field Emission Scanning Electron (FESEM) technology reveal tiny grains aggregated together that are in qualitative accord with the crystalline sizes determined by XRD analysis. Energy dispersive X-ray (EDX) analysis has observed the presence of constituent elements in the prepared films. The results of the photoluminescence (PL) experiments demonstrate the quality of the crystal structure and the presence of defects in the films. According to the absorption measurements, two-band gap values are determined in the range of 1.55 to 1.25 eV and in the range of 2.0 to 2.0 eV for different Ni doping concentrations, respectively. The maximum photoconductive parameters such as photo-responsivity (R), external quantum efficiency (EQE), and detectivity (D*) of 1.64 × 10⁻¹AW⁻¹, 38%, and 9.273 × 10⁸ Jones were achieved for 8% Ni-doped Co₃O₄ sample. The results obtained in the present study indicate that the 8% Ni-doped Co₃O₄ sample finds suitable material for photodetector devices.