Effect of ZnS nanoparticles on the Judd-Ofelt and radiative parameters of Ho${}^{3+}$ ions in sol-gel silicate matrix

Ho${}^{3+}$ ions doped with ZnS NPs in silicate glasses prepared by room temperature sol-gel method, and its physical parameters and spectroscopic properties were characterized. Structural characterization were performed by XRD, FTIR, SEM, EDX and TEM. ZnS nanoparticles are present in the Ho${}^{3+}$-doped silicate matrix, according to structural investigations. The phenomenological Judd Ofelt intensity parameters Ω${}_{\lambda }$, which depict the intensities for transitions in lanthanides and actinides in both solids and liquids, follow the pattern Ω${}_2$ > Ω${}_4$ > Ω${}_6$, according to Judd Ofelt analysis of UV-Visible absorption spectra. The study reveals that the four unique PL emission bands of Ho${}^{3+}$ are significantly influences by the concentration of ZnS NPs for enhancing PL emissions is found to be 20 M. This enhancement is ascribed to the modification of the network and sensitization of Ho${}^{3+}$ ions by the presence of the NPs. The photoluminescence spectra of the prepared samples were used to calculate the radiative parameters, such as the stimulated emission cross-section (σ${}_p$), radiative lifetimes (τ${}_R$), branching ratio (β${}_R$), and transition probability (A${}_{ed}$). CIE color coordinates were computed and they showed the yellow to greenish-yellow region for Ho${}^{3+}$ doped with various ZnS concentration. The present, SHZ20 glass may be useful for the greenish-yellow emitting phosphor application. The result of the Figure of Merit indicate that the prepared glasses show promise for use as optical amplifiers.