Enhancement of blue upconversion luminescence in hexagonal NaYF4:Yb,Tm by using K and Sc ions

Kale, Vishal; Soukka, Tero; Hölsä, Jorma; Lastusaari, Mika

doi:10.1007/s11051-013-1850-8

Cited by 28 publications

(17 citation statements)

References 49 publications

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“…For this study, we used two different UCPs: a visible-light emitter (NaYF 4 :Yb 3+ ,Er 3+ ), [25] hereafter referred to as UCP-Vis (see Figure S1 in the Supporting Information), and a UVlight emitter (Na 0.6 K 0.4 YF 4 :Yb 3+ ,Tm 3+ ), [26] hereafter referred to as UCP-UV (see Figure S2). Both were used with appropriate initiator systems, whereby the emission wavelength of the UCPs must overlap with the absorption wavelength of the initiator (see Figures S3 and S4).…”

Section: In Memory Of Daniel Thomasmentioning

confidence: 99%

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

et al. 2014

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We present a straightforward and generic strategy for coating upconverting nanoparticles (UCPs) with polymer shells for their protection, functionalization, conjugation, and for biocompatibility. UCPs are attracting much attention for their potential use as fluorescent labels in biological applications. However, they are hydrophobic and non-compatible with aqueous media; thus prior surface modification is essential. Our method uses the internal UV or visible light emitted from UCPs upon photoexcitation with near-infrared radiation, to locally photopolymerize a thin polymer shell around the UCPs. In this way, a large variety of monomers with different chemical functionalities can be incorporated. If required, a second layer can be added on top of the first. Our method can provide a large spectrum of surface functional groups rapidly and in one pot, hence offering a platform for the preparation of libraries of functional polymer-encapsulated UCPs for applications in bioassays, biosensing, optical imaging, and theranostics.

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Section: In Memory Of Daniel Thomasmentioning

confidence: 99%

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

et al. 2014

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“…The synthesis protocol for the UCNPs was been adopted from our previously published procedure. 29 Briefly, the syntheses of 0.5% Tm doped NaY 1-x Yb x F 4 UCNPs were done by stepwise substitution of Y 3+ by 20, 40, 60, 80 and 100% of the sensitizer ion Yb 3+ (the percentage of Yb 3+ is with respect to the total rare earth contents excluding the activator). In a typical experiment, 0.2 moldm -3 RCl 3 ·6H 2 O (R:Y and/or Yb, Tm) in methanol were added to a 250 cm 3 two neck round-bottom flask containing 9 cm 3 oleic acid (OA) and 21 cm 3 1-octadecene (ODE).…”

Section: Materials Synthesismentioning

confidence: 99%

Intense UV upconversion through highly sensitized NaRF₄:Tm (R:Y,Yb) crystals

et al. 2015

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Photon upconverting luminescent hexagonal NaRF4:Tm (0.5 mol%) (R:Y 3+ ,Yb 3+ ) crystals with Yb 3+ concentrations between 20 and 99.5 mol% were synthesized by a modified thermal coprecipitation method. The effect of the Yb 3+ sensitizer concentration on the shape, size, structure, upconversion luminescence intensities and dynamic luminescence lifetimes were studied in detail. The intensity of ultraviolet upconversion luminescence at 340-365 nm upon 980 nm excitation increased up to 20 times with increasing Yb 3+ concentration. The mechanisms for the changes in morphology, size and UV upconversion emission are discussed. In addition, the effect of the Tm 3+ concentration on the UV emission of NaYbF4 crystals was investigated. The results demonstrate that the NaYbF4 with Tm 3+ concentration between 0.4 to 0.8 mol% produce the most intense UV upconversion luminescence. These crystals may find applications in e.g. UV-visible solid state lasers or as an internal UV radiation source for many photochemical reactions.

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“…For this study, we used two different UCPs: a visible‐light emitter (NaYF 4 :Yb 3+ ,Er 3+ ),25 hereafter referred to as UCP‐Vis (see Figure S1 in the Supporting Information), and a UV‐light emitter (Na 0.6 K 0.4 YF 4 :Yb 3+ ,Tm 3+ ),26 hereafter referred to as UCP‐UV (see Figure S2). Both were used with appropriate initiator systems, whereby the emission wavelength of the UCPs must overlap with the absorption wavelength of the initiator (see Figures S3 and S4).…”

Section: Functionalized Water‐compatible Core–shell Ucps Obtained By mentioning

confidence: 99%

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

et al. 2014

Self Cite

View full text Add to dashboard Cite

We present a straightforward and generic strategy for coating upconverting nanoparticles (UCPs) with polymer shells for their protection, functionalization, conjugation, and for biocompatibility. UCPs are attracting much attention for their potential use as fluorescent labels in biological applications. However, they are hydrophobic and non‐compatible with aqueous media; thus prior surface modification is essential. Our method uses the internal UV or visible light emitted from UCPs upon photoexcitation with near‐infrared radiation, to locally photopolymerize a thin polymer shell around the UCPs. In this way, a large variety of monomers with different chemical functionalities can be incorporated. If required, a second layer can be added on top of the first. Our method can provide a large spectrum of surface functional groups rapidly and in one pot, hence offering a platform for the preparation of libraries of functional polymer‐encapsulated UCPs for applications in bioassays, biosensing, optical imaging, and theranostics.

show abstract

Enhancement of blue upconversion luminescence in hexagonal NaYF4:Yb,Tm by using K and Sc ions

Cited by 28 publications

References 49 publications

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

Intense UV upconversion through highly sensitized NaRF₄:Tm (R:Y,Yb) crystals

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

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Enhancement of blue upconversion luminescence in hexagonal NaYF4:Yb,Tm by using K and Sc ions

Cited by 28 publications

References 49 publications

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

Intense UV upconversion through highly sensitized NaRF4:Tm (R:Y,Yb) crystals

Versatile Synthetic Strategy for Coating Upconverting Nanoparticles with Polymer Shells through Localized Photopolymerization by Using the Particles as Internal Light Sources

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Intense UV upconversion through highly sensitized NaRF₄:Tm (R:Y,Yb) crystals