A comparative analysis of optical and electrical properties of pure CuO and Zn doped CuO nanoparticles for optoelectronic device applications

A sol-gel auto-combustion was used to prepare both pure and Zn-doped CuO NPs. The effect of Zn²⁺ on the electrical properties was investigated for use in optoelectronic device applications. The XRD analysis exhibited the synthesized CuO has a single monoclinic phase with a ZnO secondary phase. SEM micrographs show the spherical and cubic structure of the pure and Zn-doped CuO NPs, respectively. The average crystalline size, lattice constants, dislocation density, and microstrain were measured in the range of 25.23–21.18 nm, 7.893–7.745 A°, 1.57–2.22 × 10¹⁵m⁻² and −3.55 × 10⁻⁴× to –4.34 × 10⁻⁴, respectively. The Raman results revealed that sharper and stronger peaks were detected which also shifted to higher wavenumbers with declining particle size which are well matched to XRD results and revealed the pureness of the samples. The band gap was estimated with Tauc’s equation, and the findings showed that the addition of Zn²⁺ ions increased the band gap’s energy from 1.47 eV to 1.62 eV. To ascertain the electrical characteristics of produced nanoparticles, electrical characteristic investigations were carried out. From the consequences, it has been analyzed that electrical resistivity enhanced from 9.12 × 10³ to 4.84 × 10⁴ Ω cm with the addition of Zn in CuO. Based on the obtained consequences, it can be predicted that the modified electrical and optical properties of the prepared CuO nanoparticles can make them a potential candidate for optoelectronic applications, if control the generation of secondary phase, band gap enhancement, and generation of oxygen vacancies, because these factor influences the charge carrier’s mobility.

Graphical Abstract