Iron oxide-induced thermal effects on solid-state upconversion emissions in NaYF4:Yb,Er nanocrystals

Area of Science:

• Materials Science
• Nanotechnology
• Photonics

Background:

• Photon upconversion materials offer potential for biological imaging and sensing.
• Sodium yttrium fluoride (NaYF4) doped with ytterbium (Yb) and erbium (Er) are common upconverting nanoparticles.
• Hybrid nanomaterials integrate different components to achieve enhanced functionalities.

Purpose of the Study:

• To investigate the solid-state upconversion emission of NaYF4:Yb,Er nanoparticles mixed with iron oxide nanoparticles.
• To understand the influence of iron oxide on the upconversion properties of NaYF4:Yb,Er nanoparticles.
• To explore the thermal effects in mixed nanoparticle systems.

Main Methods:

• Prepared mixtures of Fe3O4 nanoparticles (6 nm) and NaYF4:Yb,Er nanoparticles (10 or 50 nm) in varying ratios.
• Fabricated samples by drying chloroform solutions of nanoparticles onto glass slides.
• Acquired upconversion spectra and analyzed laser power-dependent emission and temperature-sensitive spectral features.

Main Results:

• Observed laser power-dependent upconversion emission correlated with iron oxide content.
• Monitored lattice temperature changes using the relative intensities of specific spectral transitions.
• Demonstrated an iron oxide-induced thermal effect influencing upconversion, dependent on laser power and Fe3O4 proportion.

Conclusions:

• Iron oxide nanoparticles induce a thermal effect in NaYF4:Yb,Er nanoparticles, altering their upconversion emission.
• This thermal effect is controllable by laser power and the concentration of iron oxide.
• Consideration of thermal effects is crucial for designing luminescent upconverting hybrid materials.