Strong upconverting and downshifting emission of Mn²⁺ ions in a Yb,Tm:NaYF₄@NaLuF₄/Mn:CsPbCl₃ core/shell heterostructure towards dual-model anti-counterfeiting

Abstract

Herein, Yb,Tm:NaYF4@NaLuF4/Mn:CsPbCl3 quasi-core/shell heterostructure are synthesized by assistance of silica. The strong upconverting and downshifting emission of Mn2+ ions was observed in the nanocomposite with quasi-core/shell structure. The FRET process...

High-Efficiency and Wavelength-Tunable Near-Infrared Emission of Lanthanide Ions Doped Lead-Free Halide Double Perovskite Nanocrystals toward Fluorescence Imaging

“…Furthermore, the time-resolved spectra of lanthanide ions doped Cs 2 AgIn 0.99 Bi 0.01 Cl 6 DPNCs were measured (Figure S4), and the monitored wavelengths were at 630 nm. The PL lifetime curves were fitted by biexponential functions: …”

High‐Efficiency Dual‐Mode Polychromatic Emission of Rare‐Earth‐Based Double Perovskite with Low Phonon Energy toward High‐Level Anti‐Counterfeiting and Information Encryption

“…In Figure a, under excitation of 980 nm, the UC PL spectra of the single crystals doped with different concentrations of Er 3+ show that the optimum concentration is 30% Er 3+ . Then, the UC PL decay curves monitoring at 551 and 667 nm were characterized for all samples (Figure 2b,c), which were well fitted by the formula [ 9 ] $$\[ \begin{array}{*{20}{c}}{I\left( {\rm{t}} \right)\; = \;{I_0}\; + \;{A_1}\exp \left( { - {\rm{t}}/{\tau _1}} \right)\; + \;{A_2}\exp \left( { - t/{\tau _2}} \right)}\end{array} \]$$where, I 0 is the original fluorescence intensity, A 1 and A 2 are obtained by experimental results. τ 1 and τ 2 represent the fast and slow decay process, associated to quenching and radiative recombination of rare earth ions, respectively.…”

“…τ 1 and τ 2 represent the fast and slow decay process, associated to quenching and radiative recombination of rare earth ions, respectively. [ 6a ] The average lifetimes of all DPSCs with different Er 3+ doping concentrations were calculated by the following equation [ 9 ] $$\[ \begin{array}{*{20}{c}}{\tau \; = \;\frac{{{A_1}\tau _1^2 + {A_2}\tau _2^2}}{{{A_1}{\tau _1} + {A_2}{\tau _2}}}}\end{array} \]$$…”

Stable and Efficient Upconversion Single Red Emission from CsPbI3 Perovskite Quantum Dots Triggered by Upconversion Nanoparticles

“…To realize the display of dual anticounterfeiting application, uniform mixtures of ink were prepared by mixing the as-prepared CsPbI 3 PQD/UCNP composites with blank screen-printing ink, and a series of luminescent patterns were designed and printed on a paper via the screen printing technique as reported. − Then, these patterns were irradiated by different diverse excitation modes, such as daylight (Figure b), 365 nm UV light (Figure c), and concurrent UV light and 980 nm NIR laser (Figure d). Compared to the case under daylight conditions, bright red emissions were distinctly observed when exposed to 365 nm UV light.…”