Luminescence dynamics and enhancement of the UV and visible emissions of Tm³⁺ in LiYF₄:Yb³⁺,Tm³⁺ upconverting nanoparticles

Abstract

An ideal concentration of Tm3+ was determined for LiYF4 upconverting nanoparticles to maximize UV and visible emission intensities.

BaYF5:Yb3+,Tm3+ Upconverting Nanoparticles with Improved Population of the Visible and Near-Infrared Emitting States: Implications for Bioimaging

“…Quenching phenomena would proportionally affect the higher-energy transitions, such as those from the 1 D 2 excited state, due to the sequential pathway for Tm 3+ upconversion. As reported in the literature, changes in relative intensities for these different compositions demonstrate that the 1 D 2 and 3 P 0 emissions do not change proportionally with the 3 H 4 emission by changing the Tm 3+ concentration. , Therefore, the difference in population of these levels is not due to quenching phenomena but rather are characteristic of the different hosts through their differences in interionic distances.…”

Influence of Gd3+ doping concentration on the properties of Na(Y,Gd)F4:Yb3+, Tm3+ upconverting nanoparticles and their long-term aging behavior

“…The upconversion luminescence (UCL) spectra of oleate -capped NaYF 4 :Yb 3+ ,Tm 3+ UCNP in cyclohexane usually show three prominent luminescence bands centered in 451 ( 1 D 2 → 3 F 4 transition, B1), 481 ( 1 G 4 → 3 H 6 transition, B2), and 800 ( 3 H 4 → 3 H 6 transition, NIR) nm upon excitation at 976 nm [35,36]. Luminescence spectra of the five AS samples were recorded for the three aforementioned luminescence bands.…”

Synthesis and fundamental studies of a photoresponsive oligonucleotide-upconverting nanoparticle covalent conjugate

“…LiYF 4 :Yb 3+ /Tm 3+ UCNPs were synthesized via a one-pot thermal decomposition method to yield oleate-capped nanoparticles. 17 The nanoparticles exhibit a square bipyramidal morphology with an average size of 94 AE 6.2 nm along the long axis, and a tetragonal crystal phase (Fig. 2A-C).…”

“…2A-C). The activator concentration of 0.2 mol% Tm 3+ was chosen because it has been demonstrated to yield strong UV emissions in the LiYF 4 host, 17 which is necessary for obtaining efficient energy transfer with the o-nitrobenzyl group in the oligonucleotide backbone. An azide-functionalized silica shell was grafted onto the surface of the UCNPs via a reverse-microemulsion method to impart stability in aqueous environments as well as provide a platform for click chemistry to the alkyne-functionalized oligonucleotides.…”

“…With regard to host compositions, LiYF 4 is a commonly overlooked material that facilitates strong upconversion in the UV when doped with 25 mol% Yb 3+ and 0.2 mol% Tm 3+ . 17 The upconverted emissions at 345 and 360 nm from the 1 I 6 -3 F 4 and 1 D 2 -3 H 6 transitions of Tm 3+ have been used for a wide variety of photochemistry applications that require in situ UV activation. 18,19 Of particular interest, the UV emissions from Tm 3+ exhibit excellent spectral overlap with the photocleavable o-nitrobenzyl linker, which is well-known for its photocaging applications.…”