Investigating the modified opto-physical response of nickel oxide by cobalt doping for high-performance photodetectors

A detailed investigation is conducted on the opto-physical response of nickel oxide with the doping of Co metal ions for efficient use in photodetector device applications. The effect of Co doping on the opto-physical response of NiO nanoparticles was studied by varying the doping concentration (x = 0.00, 0.03, and 0.05). Additionally, the reduction in band gap (3.03–2.56 eV) increases in light absorbance, increases in electrical conductivity (5.20 × 10⁻⁴ to 8.92 × 10⁻⁴ Ʊ cm⁻¹), and a reduction in charge recombination by cobalt substitution within the NiO host lattice, as confirmed from photoluminescence spectra. As a result, the opto-physical response of NiO nanoparticles improved with the increase in Co concentration. Hence, the modified opto-physical response of Co-doped NiO suggests it as a potential material for efficient utilization in photodetector applications.