Bulk SiO₂-PbF₂ oxyfluoride glasses co-doped with dispersed luminescent Ag nanoclusters and Tm³⁺ ions have been prepared by conventional melt-quenching method. Luminescence from 400 to 900 nm has been excited in this glass by UV light from 340 to 400 nm. The prepared glass has potential for application as a low cost glass phosphor in Hg-free white light generation in UV-driven devices, flexible monitors and as down-shifting layers for enhanced solar cells. Co-doping with Tm³⁺, which has an absorption band ³H₆→¹D₂, affects the tint of the total Ag-Tm³⁺ white emission band of this glass by changing the excitation wavelength to about 365 nm, which is almost the same wavelength as that of a commercial LED.

Bulk SiO₂–PbF₂ glass doped homogeneously with luminescent Ag nanoclusters has been synthesized using a melt-quenching technique. A broad range of luminescence from 400 nm to 900 nm can be excited with a broad range of UV and some visible excitation wavelengths. The luminescence spectra have been found to be invariant with excitation wavelength at room temperature, indicating a negligible distribution of Ag cluster sites. The UV excitation efficiency of Ag nanoclusters has been determined by shifting the absorption edge further into the UV using an Al₂O₃ glass-network modifier. The prepared glass is proposed as a low-cost glass phosphor for Hg-free environmentally-friendly white light generation in UV/blue-driven light emitting diodes, in flexible monitors and as down-shifting layers for enhanced solar cells.

We have measured and fitted the kinetics of luminescence of Ag nanoclusters homogeneously dispersed within the bulk of an oxyfluoride glass, with various sample temperatures. The balance equations for the populations of the excited singlet and triplet states of the Ag nanoclusters are proposed and used in this fitting while taking into account inter-system crossing between the singlet and triplet states and their wavelength dependent spontaneous decay to the ground singlet state. The involved energy barriers and rate constants and spontaneous emission cross-sections for the excited singlet and triplet states are evaluated.

The combination of photothermal and magnetic functionalities in one biocompatible nanoformulation forms an attractive basis for developing multifunctional agents for biomedical theranostics. Here, we report the fabrication of silicon–iron (Si-Fe) composite nanoparticles (NPs) for theranostic applications by using a method of femtosecond laser ablation in acetone from a mixed target combining silicon and iron. The NPs were then transferred to water for subsequent biological use. From structural analyses, it was shown that the formed Si-Fe NPs have a spherical shape and sizes ranging from 5 to 150 nm, with the presence of two characteristic maxima around 20 nm and 90 nm in the size distribution. They are mostly composed of silicon with the presence of a significant iron silicide content and iron oxide inclusions. Our studies also show that the NPs exhibit magnetic properties due to the presence of iron ions in their composition, which makes the formation of contrast in magnetic resonance imaging (MRI) possible, as it is verified by magnetic resonance relaxometry at the proton resonance frequency. In addition, the Si-Fe NPs are characterized by strong optical absorption in the window of relative transparency of bio-tissue (650–950 nm). Benefiting from such absorption, the Si-Fe NPs provide strong photoheating in their aqueous suspensions under continuous wave laser excitation at 808 nm. The NP-induced photoheating is described by a photothermal conversion efficiency of 33–42%, which is approximately 3.0–3.3 times larger than that for pure laser-synthesized Si NPs, and it is explained by the presence of iron silicide in the NP composition. Combining the strong photothermal effect and MRI functionality, the synthesized Si-Fe NPs promise a major advancement of modalities for cancer theranostics, including MRI-guided photothermal therapy and surgery.

Dy³⁺-doped, Ag and Dy³⁺-co-doped, and Tm³⁺ and Dy³⁺-co-doped oxyfluoride glasses have been prepared by a conventional melt-quenching method. White and yellowish light emissions were generated in the glasses under excitation in the range from 350 to 390 nm. Changes in the excitation wavelength in the ultraviolet (UV) range do not significantly alter the emission tint of the Dy and Ag and Dy-co-doped glasses. On the contrary, the tint of the Tm and Dy co-doped glasses considerably varies under excitation in the same range.

Silver and lanthanide (Tm³⁺, Yb³⁺) doped oxyfluoride glasses have been prepared by melt-quenching method. The absorption of the glasses was measured in the range from 350 to 550 nm revealing the absorption edges of Ag nanoclusters and Tm³⁺ transition. The photoluminescence spectra of the glasses were detected in the range from 400 to 1100 nm under excitation in the range from 300 to 500 nm. The photoluminescence excitation spectra showed that Ag nanoclusters and Tm³⁺ ions can effectively harvest energy in UV-range and convert to visible and infrared (through emission by Yb³⁺ ions) ranges making the glasses perspective as white light emitters and solar spectrum downconverters.