Enhancement of Sm 3+ Luminescence in Sol-Gel Silica Matrix: Effect of Ligands Phenyl Phosphinic Acid and Trioctylphosphine Oxide

• Published in: Journal of fluorescence 2024-12
• Main Authors: Rajkonwar, Navaneeta, Gogoi, Purabi, Dutta, Pankaj
• Format: Article
• Language: English
• ISSN: 1573-4994
• DOI: 10.1007/s10895-024-04076-y

Sol-gel silica matrices singly doped with Sm and co-doped with ligands phenyl phosphinic acid (PPIA) and trioctylphosphine oxide (TOPO) were fabricated and studied for their structural and spectroscopic behaviour. Structural studies were done by x-ray diffraction (XRD) and Fourier transform infra-red (FTIR) absorption analysis whereas spectroscopic behaviour was studied by ultraviolet - visible (UV-Vis) absorption, photoluminescence (PL) excitation, emission and time-correlated decay analyses. XRD studies exhibit the amorphous nature of the samples and FTIR studies corroborate the presence of the ligands in the silica matrix. UV-Vis absorption and PL studies show significant enhancement in the radiative parameters in ligand co-doped samples compared to singly doped Sm sample. Judd Ofelt parameters estimated from the absorption spectra possess higher values compared to popular hosts; revealing higher asymmetry and covalency around the active Sm ions. An enhancement in PL intensity by 50.38 times and yield by 52.57 times with the co-doping of the ligands PPIA and TOPO is reported. These enhancement in the radiative output in ligand co-doped samples is attributed to the modification of the silica network with the incorporation of the ligands, energy transfer from ligands to nearby Sm ions as well as due to the shielding of Sm ions from the OH quenchers in the silica matrix. The improved PL behaviour especially corresponding to G → H transitions occurring at 643 nm suggests the potential of PPIA and TOPO co-doped Sm silica matrix for diverge optical applications.