<p>Blended polymers of polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP)/tetrabutylammonium iodide (TBAI)/Zn_0.95Mg_0.05O/Cu_1-xNi_xO have been constructed for utilization in numerous promising optoelectronic applications. The structure and morphology of PVA/PVP/TBAI/Zn_0.95Mg_0.05O/Cu_1-xNi_xO blended polymers were explored. The sample including 5% Ni (<i>x</i> = 0.05) displayed the highest absorbance (0.6 a.u. at ~ 500 nm) within the visible spectrum. The direct and indirect optical band gap values of the PVA/PVP/TBAI blended polymer loaded with Zn_0.95Mg_0.05O/Cu_1-xNi_xO exhibited an uneven decrease. The ultimate refractive index at 600 nm reached ~ 1.56 in the 5% Ni sample, compared to ~ 1.37 for the undoped blend. The Wemple and DiDomenico (WDD) model was utilized to investigate the dispersion of the refractive index in the samples. The blended polymer with 5% Ni showed an elevated real portion of the dielectric constant (<i>ε</i>_r) value in the visible spectrum. The blended polymer filled with Zn_0.95Mg_0.05O/Cu_1-xNi_xO demonstrated the greatest values for the imaginary portion of the dielectric constant (<i>ε</i>_i) and the energy loss functions (SELF and VELF). The optical conductivity (<i>σ</i>_opt) values are maximized in the modified blended polymer containing Zn_0.95Mg_0.05O/CuO. The sample containing 5% Ni displayed the greatest values of the nonlinear optical (NLO) parameters. The third-order nonlinear susceptibility (χ⁽³⁾) was maximized (~ 2.8 × 10⁻¹⁴ esu at ~ 600 nm) for the 5% Ni sample. The fluorescence intensity of PVA/PVP/TBAI dropped irregularly when doped with Zn_0.95Mg_0.05O/Cu_1-xNi_xO. Under 320 nm, an additional fluorescence peak emerged at 470 nm due to the doping procedure. The intensities of these peaks exhibited an uneven rise with the augmentation of Ni in the filler. The possible conduction mechanisms in all samples were examined.</p>