Manipulating the Injected Energy Flux via Host-Sensitized Nanostructure for Improving Multiphoton Upconversion Luminescence of Tm³⁺

Abstract

Combating the concentration quenching effect by increasing the concentration of sensitized rare-earth ions in rational design upconversion nanostructure will make it easier to utilize injection energy flux and transfer it to emitters, resulting in improved upconversion luminescence (UCL). We proposed a host-sensitized nanostructure (active core@luminescent shell@inert shell) to improve multiphoton UCL of Tm3+ based on the LiLnF4 host. Yb3+ ions were isolated in the core as energy absorbents, and Tm3+ was doped in the interior LiYbF4 host shell. Compared with sandwich structured nanocrystals (Y@Y:Yb/Tm@Y), reverse structure (YbTm@Yb@Y), and fully doped structure (YbTm@YbTm@Y), the proposed structure achieved the highest efficiency of multiphoton UCL and favored a better FRET-based application performance as the Tm3+ located at an optimized spatial distribution. Furthermore, steady-state and dynamic analysis results demonstrate that by manipulating the spatial distribution of the active ions, excited energy can be tuned to enable multiphoton upconversion enhancement, overcoming the conventional limitations.

Tm3+ mediated multicolor luminescence of NaYbF4:Er,Tm@NaYF4 for advanced anti-counterfeiting

“…In addition, when there was no or a small amount of Er 3+ , Tm 3+ acted as an activator and emitted blue light. 29,30 Therefore, by changing the mediating action of Tm 3+ in Yb 3+ /Er 3+ /Tm 3+ codoped UCNPs, it is expected that multi-color anti-counterfeiting with significant changes in luminescence color can be achieved.…”

Bright Tm3+-based downshifting luminescence nanoprobe operating around 1800 nm for NIR-IIb and c bioimaging

“…1a ). It should be noted that Tm 3+ is one of the few RE 3+ ions that exhibit different spectral conversions of interest ranging from the UV 21 , 22 to the mid-infrared regions 23 , 24 . The commonly reported Stokes or downshifting luminescence (DSL) of Tm 3+ in the NIR-II region is located at 1450 nm ( 3 H 4 → 3 F 4 , a weak transition), and it shows a low luminescence efficiency and competes with strong water absorption in this region (Fig.…”

Multifunctional Laser-Induced Bubble Microresonator for Upconversion Emission Enhancement

“…The importance and versatility of upconversion nanoparticles (UCNPs) have been proven in various applications ranging from displays, bioimaging, sensing, optoelectronics, , photovoltaics, photocatalysis, , therapeutics, , and diagnostics . UCNPs can exhibit antistokes emissions under near-infrared (NIR) excitation. − They are capable of emitting ultraviolet and visible photons by absorbing multiple NIR photons due to their multiple energy levels or ladder-like energy level systems. , However, the quantum yield of the upconversion emission is generally low due to the multiphoton processes and low absorption cross-section, which hinders the applications of UCNPs.…”