Emission stability and reversibility of upconversion nanocrystals

Abstract

We report the emission stability and reversibility of NaYF4:Yb3+,Er3+ core and core–shell nanocrystals at different temperatures and pH values.

Hexagonal β-Na(Y,Yb)F4 based core/shell nanorods: epitaxial growth, enhanced and tailored up-conversion emission

“…This results from surface passivation effects. 8,33,34 The enhanced intensity of Er 3+ was attributed to the increased content of precursor. From the corresponding luminescence photographs, as shown in Fig.…”

Combinations of Superior Inorganic Phosphors for Level‐Tunable Information Hiding and Encoding

“…Better thermostability of core/shell UCNPs also reveals that the introduction of a protective shell is beneficial for achieving excellent photostability. [ 142 ] Based on this concept, a phospholipid bilayer (PLM) is assembled onto the NaYF 4 :Er 3+ /Yb 3+ @NaYF 4 core/shell UCNPs by a self‐assembling way, in Figure a. The NaYF 4 :Er 3+ /Yb 3+ @NaYF 4 @PLM UCNPs keep high UCL intensity retention in various solutions even up to 96 h. [ 143 ] It reveals that the construction of double protective shells composed of an inert shell (prevent energy transfer from a core to surface) and a hydrophobic layer (isolate water molecule) is effective to improve the waterproof properties.…”

“…Better thermostability of core/shell UCNPs also reveals that the introduction of a protective shell is beneficial for achieving excellent photostability. [142] Based on this concept, a phospholipid bilayer (PLM) is assembled onto the NaYF 4 :Er 3+ / Yb 3+ @NaYF 4 core/shell UCNPs by a self-assembling way, in Figure 7a. The NaYF 4 :Er 3+ /Yb 3+ @NaYF 4 @PLM UCNPs keep high UCL intensity retention in various solutions even up to [143] Copyright 2020, American Chemical Society.…”

Weakening thermal quenching to enhance luminescence of Er3+ doped β‐NaYF4 nanocrystals via acid‐treatment

“…More importantly, the surface organic ligands are one of the main reasons of thermal quenching. At higher temperature, the increased activity of surface organic ligands vibration could broadly limit luminescent efficiency through nonradiative relaxation pathways . Besides, the carbonization of surface organic ligands blackening NCs also could reduce excitation and emission efficiency.…”

“…At higher temperature, the increased activity of surface organic ligands vibration could broadly limit luminescent efficiency through nonradiative relaxation pathways. 30,31 Besides, the carbonization of surface organic ligands blackening NCs also could reduce excitation and emission efficiency. Hence, it is imperative to find a way to reduce the role of surface organic ligands in thermal quenching.…”