Nanoparticles of ZrO2:xSr2+ produced by the sonochemical method: Structural, morphological, and photoluminescent characterization for optoelectronic applications

Abstract

The pursuit of efficient materials for technological applications is essential. Among these materials, zirconia emerges as a promising candidate with potential for several applications, from applications related to mechanical resistance to optoelectronic applications. By introducing dopants into this compound, it becomes feasible to modulate its inherent properties. In this study, ZrO2 doped with strontium was synthesized for the first time via the sonochemical method at different percentages in mol (1, 2, 4, and 8 mol%). Analysis via X-ray diffraction (XRD) and Raman spectroscopy unveiled the formation of both monoclinic and tetragonal phases, with the latter being stabilized through the incorporation of the dopant element. In addition to observing irregular morphology through scanning electron microscopy (SEM-FEG), a reduction in particle size was also evidenced following the introduction of Sr2+ ions, a phenomenon corroborated via Rietveld refinement. The reflectance spectra of the doped samples exhibited an optical absorption tail characterized by the Urbach energy (EU), indicating an increase in structural disorder in the samples. The photoluminescence (PL) results indicated that the introduction of Sr2+ ions into the ZrO2 matrix induced modifications in the characteristics of the spectrum profile. The phase transformation observed in XRD was reflected in the changes observed in the photoluminescent behavior of the samples, which emitted light between the blue and green regions.