Structural characteristics and enhanced two-photon absorption behavior of Pb-doped ZnMoO₄ nanostructures for optoelectronic device applications

We investigate the nonlinear optical response of Pb²⁺-doped ZnMoO₄ nanostructures synthesized by chemical precipitation technique. X-ray diffraction (XRD) and Raman spectroscopy results confirm the formation of ZnMoO₄ nanostructures with a triclinic structure. High-Resolution Transmission electron microscope (HRTEM) reveals the deformed spherical shape of nanostructures. Further, the successful doping and molecular bonding of Pb²⁺ with ZnMoO₄ was evidenced by FTIR and XPS. UV–Vis absorption spectra reveals the alteration in the electronic band structure of ZnMoO₄ nanostructures upon Pb doping, leading to a considerable increase in bandgap and enhanced charge transfer within ZnMoO₄: Pb nanostructure. The nonlinear optical absorption and optical limiting characteristics of the nanoparticles is measured via the open aperture Z-scan technique with an Nd: YAG pulsed laser at 532 nm, exhibiting a reverse saturable absorption and a rapid decrease in the commencement of the optical limiting threshold with the increased in Pb concentration. The observed nonlinear absorption can be attributed to the crystal structure, particle size, creation of oxygen vacancies, and defects on the host lattice. These results suggest that Pb²⁺-doped ZnMoO₄ nanoparticles have excellent prospects for optical limiting (OL) applications. This could be useful for applications such as laser protection and optoelectronic device applications.