Tailoring CuO/Polyaniline Nanocomposites for Optoelectronic Applications: Synthesis, Characterization, and Performance Analysis.

This research focuses on creating CuO/PANI nanocomposite films by electrodepositing copper oxide nanoparticles into a polyaniline matrix on ITO substrates. The CuO nanoparticle content was adjusted between 7% and 21%. These nanocomposites are promising for various applications, such as optoelectronic devices, gas sensors, electromagnetic interference shielding, and electrochromic devices. We utilized UV-Vis spectroscopy to examine the nanocomposites' interaction with light, allowing us to ascertain their refractive indices and absorption coefficients. The Scherrer formula facilitated the determination of the average crystallite size, shedding light on the material's internal structure. Tauc plots indicated a reduction in the energy-band gap from 3.36 eV to 3.12 eV as the concentration of CuO nanoparticles within the PANI matrix increased, accompanied by a rise in electrical conductivity. The incorporation of CuO nanoparticles into the polyaniline matrix appears to enhance the conjugation length of PANI chains, as evidenced by shifts in the quinoid and benzenoid ring vibrations in FTIR spectra. SEM analysis indicates that the nanocomposite films possess a relatively smooth and homogeneous surface. Additionally, FTIR and XRD analyses demonstrate an increasing degree of interaction between CuO nanoparticles and PANI chains with higher CuO concentrations. At lower concentrations, interactions were minimal. In contrast, at higher concentrations, more significant interactions were observed, which facilitated the stretching of polymer chains, improved molecular packing, and facilitated the formation of larger crystalline structures within the PANI matrix. The incorporation of CuO nanoparticles resulted in nanocomposites with electrical conductivities ranging from 1.2 to 17.0 S cm^-1, which are favorable for optimum performance in optoelectronic devices. These results confirm that the nanocomposite films combine pronounced crystallinity, markedly enhanced electrical conductivity, and tunable band-gap energies, positioning them as versatile candidates for next-generation optoelectronic devices.