Intrinsic single-band upconversion emission in colloidal Yb/Er(Tm):Na3Zr(Hf)F7 nanocrystals

Abstract

Novel Yb/Er(Tm):Na(3)MF(7) (M = Zr, Hf) nanocrystals with intrinsic single-band upconversion emission, in contrast to the routine lanthanide-doped fluoride nanocrystals which show typical multi-band upconversion emissions, are reported for the first time. Specifically, the red upconversion intensity of the Yb/Er:Na(3)ZrF(7) nanocrystals is about 5 times as high as that of the hexagonal Yb/Er:NaYF(4) ones with a similar crystal size.

Localization induced intense red upconversion luminescence in monodispersed K3ZrF7:Yb3+/Er3+ nanocrystals

“…Recently, the UCL was found to be greatly enhanced through the localization of rare earth ions in discrete sub-cluster in orthorhombic-phase KYb 2 F 7 [16]. Similarly, interesting pure red UCL was observed from Er 3+ ions in Na 3 ZrF 7 or Na 3 HfF 7 nanocrystals due to the rich population 4 F 9/2 state by the prominent Er 3+ -Er 3+ cross-relaxation within Zr or Hf sub-clusters [17]. Cubic K 3 ZrF 7 also possesses intrinsic Zr 4+ sub-cluster structure [18,19], thus it is expected that efficient energy transfer between Ln 3+ ions incorporated into the Zr 4+ sites will be readily achieved.…”

Eu3+ and Er3+ doped NaLu1Yb F4 (x= 0 ∼ 1) solid-solution self-crystallization nano-glass-ceramics: Microstructure and optical spectroscopy

“…Therefore, searching highly efficient UC materials is highly valuable. It is well known that the crystals structures affect the UC luminescence performance, so it is particularly important to choose the appropriate host materials [7][8][9][10]. Oxyfluoride glass ceramics (GCs) combine the advantage of the mechanical and chemical stability of the oxide glass and the low phonon energy of the precipitated fluoride crystal, which may become a desirable choice as the UC bulk hosts [11][12][13][14][15][16][17][18][19][20][21][22][23].…”

Novel Upconversion Behavior in Ho3+‐Doped Transparent Oxyfluoride Glass‐Ceramics Containing NaYbF4 Nanocrystals

“…Over the past decades, rare‐earth (RE) ions‐doped upconversion materials have attracted much attention for a wide range of applications, such as all‐solid compact lasers, color displays, upconversion phosphors, and biomedical imaging . RE fluorides are identified as the most efficient host matrices for upconversion because of their low phonon energy, excellent valence state, and ionic radius for RE ions doping .…”

“…Over the past decades, rare‐earth (RE) ions‐doped upconversion materials have attracted much attention for a wide range of applications, such as all‐solid compact lasers, color displays, upconversion phosphors, and biomedical imaging . RE fluorides are identified as the most efficient host matrices for upconversion because of their low phonon energy, excellent valence state, and ionic radius for RE ions doping . Recently, transparent oxyfluoride glass‐ceramics have been considered potential hosts for RE ions doping owing to the fact that they combine advantages of superior chemical and mechanical stability of oxide glasses and low phonon energy of fluoride nanocrystals .…”