Enhanced photo detection performance of Fe doped Co₃O₄ thin films prepared via the nebulizer spray pyrolysis method

The development of nanofabrication technologies has ushered in a new era for UV photodetectors, offering exceptional precision, low energy consumption, and significant miniaturization. In this study, we report the successful fabrication of high-quality Fe-doped Co₃O₄ thin-films for UV photodetectors on glass substrates using the eco-friendly nebulizer-assisted spray pyrolysis (NSP) method, with Fe doping concentrations ranging from 0 % to 5 % by weight. To elucidate the effects of Fe doping, we employed standard characterization techniques to comprehensively investigate the structural, morphological, and optoelectronic properties of the resulting thin films. XRD analysis of the samples confirms a cubic phase structure, with higher intensity peaks along (111) and (311) orientations. The crystallite size ranges from 40 nm for the undoped Co₃O₄ film to 50 nm for the 4 wt% Fe-doped film. The FESEM images distinctly display a smooth and compact grain structure with minimal porosity nature for all doping levels in the Co₃O₄ films. The incorporation of Fe dopant significantly enhances photon absorption in the UV region. The 4 wt% Fe-doped Co₃O₄ thin film exhibits a reduced band gap of 1.82 eV. Each fabricated thin films exhibits prominent photoluminescence bands at approximately 475 nm and 640 nm. The 4 wt% Fe doped Co₃O₄ thin film demonstrated exceptional performance under 365 nm illumination, with a responsivity of 51.8 x 10⁻²AW⁻¹, detectivity of 31.5 x 10⁸ Jones and EQE of 167 %. Notably the device exhibited rapid rise and fall times of 1.42 and 1.45 s, respectively. These outstanding results highlight the potential of Fe-doped Co₃O₄ for commercial UV photo detector applications, paving the way for its expanded use in various fields.