Inhibiting concentration quenching in Yb3+-Tm3+ upconversion nanoparticles by suppressing back energy transfer

Abstract Lanthanide-doped upconversion nanoparticles are promising for applications ranging from biosensing, bioimaging to solid-state lasing. However, their brightness remains limited by the concentration quenching effect of lanthanide activator ions, which greatly restricts their utility. Here, we develop a heterogeneous core–shell–shell nanostructure based on hexagonal NaYF 4 , in which Tm 3+ activator and Yb 3+ sensitizer are separated into the core and inner shell, while the outmost shell is used to suppress surface quenching effects. We show that this design can alleviate the activator concentration quenching effect, resulting in optimal Tm 3+ concentration increasing from 1% to 8% at sub-100 W/cm 2…

• NN
  National Natural Science Foundation of China

  Awards: 52272270, 51972084
• HI
  Harbin Institute of Technology

  Award: AUGA5710052614
• UU
  Uppsala Universitet
• FR
  Fundamental Research Funds for the Central Universities

  Awards: AUGA8880100415, AUGA5710052614, XWQQ5710001615