Strong Emission Enhancement via Dual-Wavelength Coexcitation in YbTm-Doped Upconverting Nanoparticles for Near-Infrared and Subdiffraction Imaging.

ABSTRACT: Upconversion (UC) emission in lanthanide-doped nanoparticles is typically excited by a single near-infrared (NIR) wavelength, most commonly around 975 nm, which promotes ground-state absorption by Yb³⁺ sensitizer ions and subsequent energy transfer to activator ions such as Tm³⁺. However, due to the presence of multiple long-lived excited states in lanthanide ions, additional excitation wavelengths can activate or modulate further energy-transfer pathways, leading to enrichment or depletion of specific electronic level populations. Despite their significant potential, such possibilities remain underexplored. In this work, we present a dual-wavelength coexcitation approach applied to NaYF₄ upconverting nanoparticles (UCNPs) codoped with Yb³⁺ and T

SUBMITTER: Rajchel-Mieldzioc P 

PROVIDER: S-EPMC12312145 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature