Energy up-conversion in Tb3+/Yb3+ co-doped colloidal α-NaYF4 nanocrystals

Near-infrared excited luminescence and in vitro imaging of HeLa cells by using Mn2+ enhanced Tb3+ and Yb3+ cooperative upconversion in NaYF4 nanocrystals

“…The latter case is typical for Yb 3+ sensitized Eu 3+ and Tb 3+ emission, which involves cooperative energy transfer (CET). [9][10][11][12][13] These ions display unique and easily distinguishable spectral features, but CET is around 2-3 orders of magnitude less efficient in comparison to energy transfer upconversion found in the Yb 3+ -Tm 3+ /Er 3+ /Ho 3+ pairs. 14 For these reasons, terbium upconversion emission should be enhanced in order to provide labels with brightness comparable to that of Yb 3+ -Er 3+ or Yb 3+ -Tm 3+ in UCNPs and thus offer sufficient sensitivity for bioassays and bioimaging.…”

Upconversion of Rare Earth Nanomaterials

“…Hence, its UC emission efficiency is approximately three orders of magnitude lower than that of ETU (4). Sometimes cooperative UC emissions can be observed from cooperative dimers (29,30).…”

Highly Enhanced Cooperative Upconversion Luminescence through Energy Transfer Optimization and Quenching Protection

“…[11][12][13] Few articles exist on achieving efficient upconversion emission from other rare-earth ions such as Tb 3+ and Eu 3+ . [14][15][16][17] To enrich multiplex luminescence probes, one of the few solutions is based on energy migration upconversion (EMU). 18,19 Typically, Tm 3+ ions are used to accumulate photon energy and transfer it to migrators (Gd 3+ ) to activate other luminescence centers.…”