Synthesis of ultra-small BaLuF₅:Yb³⁺,Er³⁺@BaLuF₅:Yb³⁺ active-core–active-shell nanoparticles with enhanced up-conversion and down-conversion luminescence by a layer-by-layer strategy

Abstract

Ultra-small luminescent nanoparticles (NPs) are quite desirable for optoelectronic and biomedical applications.

Polyaniline-coated upconversion nanoparticles with upconverting luminescent and photothermal conversion properties for photothermal cancer therapy

“…[32][33][34][35][36][37][38] Therefore, UCNPs have been recently used as building blocks in the construction of multimodal contrast agents for imagingguided therapy. [39][40][41][42][43][44][45] In the current study, upconversion nanoparticles (UCNPs) were first prepared by a typical solvothermal method. A polyaniline photothermal therapeutic shell was then formed by the polymerization of an aniline monomer in acid aqueous conditions, thereby obtaining polyaniline-coated UCNPs (UCNPs-PANPs).…”

Synthesis of Small Ce3+-Er3+-Yb3+ Tri-Doped BaLuF5 Active-Core-Active-Shell-Active-Shell Nanoparticles with Strong Down Conversion Luminescence at 1.5 μm

“…However, when the Yb 3+ concentration in the shell was 5%, the luminescence intensity of the BaLuF 5 core-shell NPs reached its maximum value. This was due to the Yb 3+ ions in the shell could transfer energy from the pump source to the core and make a contribution to the DC emissions [31]. When the Yb 3+ concentration in the shell continuously increased from 5% to 10%, the luminescence intensity of the BaLuF 5 :Yb 3+ ,Er 3+ ,Ce 3+ core-active-shell NPs gradually decreased since the concentration quenching effect occurred [31,38].…”

“…Then, the reaction mixture was rapidly heated to 300 °C for 1 h and cooled to room temperature (RT) under an Ar flow. The reaction product was washed with cyclohexane and ethanol [31]. The finally obtained nanoparticles were dispersed into cyclohexane.…”

“…[26]. The last strategy is to increase the rate of the pump light through coating an active shell (e.g., the shell containing Yb 3+ icons) on the core NPs [27,28,29,30,31]. Zhai et al reported a method to improve the intensity BaYF 5 :Yb 3+ ,Er 3+ NPs at 1.53 μm through doping Yb 3+ ions into the BaYF 5 shell.…”

Rare earth based nanostructured materials: synthesis, functionalization, properties and bioimaging and biosensing applications

“…For example, ultra-small NaGdF 4 NPs (3-4 nm) have been produced from sodium and Gd oleates and N(CH 3 ) 4 F in a mixture of octadecene, oleic acid and oleylamine at 220°C [71], and NaGdF 4 :Yb 3+ , Er 3+ nanospheres (from 15 to 25 nm) have been synthesized from the corresponding RE oleates and NaF in octadecene and oleic acid at 320°C. The synthesis of ultra-small BaLuF 5 :Yb 3+ , Er 3+ NPs with sizes below 10 nm in octadecene/oleic acid solutions at 300°C from RE stearates has also been reported [72].…”