Towards pure near-infrared to near-infrared upconversion of multifunctional GdF_3:Yb^3+,Tm^3+ nanoparticles

Abstract

Nearly pure near-infrared to near-infrared (NIR-to-NIR) upconversion in GdF 3 host with 23% Yb 3+ and 1% Tm 3+ under 980 nm excitation is firstly reported. The ratio of the intensity of the emission at 807 nm to that at 478 nm can reach to 105, and the intensity of the emission at 807 nm is preserved. Moreover, the excitation and the emission at 980 and 807 nm are away from the visible region. These are beneficial to deeper tissue penetration and reduced autofluorescence. Raman spectroscopy measurements suggest the high probability of NIR emission in GdF 3 host. Our results indicate that the reported multifunctional nanoparticles are promising in bio-imaging and bio-separation. ©2010 Optical Society of America

NIR-to-visible and NIR-to-NIR upconversion in lanthanide doped nanocrystalline GdOF with trigonal structure

“…As mentioned for the Er 3+ /Yb 3+ sample, an ETU mechanism is very likely to be present, as schematically shown in Fig. 4 (inset [32,33] and GdF 3 [34]. In Fig.…”

Self-assembled three-dimensional NaY(WO4)2:Ln3+ architectures: Hydrothermal synthesis, growth mechanism and luminescence properties

“…As for NaY(WO 4 ) 2 :Yb 3+ /Tm 3+ (Fig. 8B), the peak at 475 nm of strong blue emission and the peak at 643 nm of weaker red emission are assigned to the transitions of 1 G 4 → 3 H 6 and 1 G 4 → 3 F 4 , respectively [21,49]. The corresponding CIE coordinates for the emission spectrum of NaY(WO 4 ) 2 :Yb 3+ /Tm 3+ are determined as x = 0.129, y = 0.108, which locate in the blue region (point d, Fig.…”

Preparation of Upconversion Nanocrystals NaYF4:Yb/Tm with Hydro(solvo)thermal Methods

“…3, upon continuous-wave excitation at 980 nm, nanocrystals prepared by solvothermal and hydrothermal methods exhibited similar UCL spectra with an excellent 800 nm near-infrared (NIR) UCL and an weak emission band at 700 nm. The emission band peaked at 700 nm was caused by 3 [22,24]. The UCL intensities of the prepared samples were measured at the same concentration of 1.0 mg/ mL in cyclohexane.…”

“…At present, many approaches for preparing lanthanide-doped UCNs have been developed, such as hydrothermal, solvothermal, thermal decomposition, and ionic liquids methods [24]. Among these approaches, thermal decomposition of trifluoroacetate precursors has the advantages of controllable size and morphology.…”