Facile synthesis of multicolor tunable ultrasmall LiYF4: Yb,Tm,Er/LiGdF4 core/shell upconversion nanophosphors with sub-10 nm size

A. Ra Hong, Su Yeon Kim, So Hye Cho, Kwangyeol Lee, Ho Seong Jang

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


Sub-10 nm-sized LiYF4:Yb,Tm/Er upconversion nanophosphors (UCNPs) and multicolor-emitting LiYF4:Yb,Tm,Er/LiGdF4 core/shell (C/S) UCNPs were facilely synthesized by using rare earth-oleate (RE(oleate)3) precursors. The size of LiYF4:Yb,Tm and LiYF4:Yb,Er UCNPs with single tetragonal phase was controlled in the range of 3.2–9.6 nm and 3.0–9.0 nm, respectivley, by varying reaction temperature from 230 to 320 °C under the use of RE(oleate)3 precursors. The sub-10 nm-sized LiYF4:Yb(25%),Tm(0.5%)/LiGdF4 (9.7 nm) and LiYF4:Yb(18%),Er(2%)/LiGdF4 (9.5 nm) C/S UCNPs were successfully synthesized from ultrasmall LiYF4-based UCNP cores smaller than 5 nm in size. The blue- and green-emitting sub-10 nm-sized LiYF4:Yb,Tm/LiGdF4 and LiYF4:Yb,Er/LiGdF4 C/S UCNPs exhibited 566 and 48,245 times higher upconversion luminescence intensities than their core counterparts, respectivley, under excitation with 980 nm near infrared light. In addition, multicolor tunable sub-10 nm-sized LiYF4:Yb,Tm,Er/LiGdF4 C/S UCNPs were synthesized and they emitted bright blue, sky blue, aquamarine, and green light by varying dopant composition (Tm and Er) and concentration.

Original languageEnglish
Pages (from-to)831-838
Number of pages8
JournalDyes and Pigments
Publication statusPublished - 2017 Apr 1


  • Core/shell structure
  • Multicolor tuning
  • Nanophosphors
  • Ultrasmall nanocrystals
  • Upconversion

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Process Chemistry and Technology


Dive into the research topics of 'Facile synthesis of multicolor tunable ultrasmall LiYF<sub>4</sub>: Yb,Tm,Er/LiGdF<sub>4</sub> core/shell upconversion nanophosphors with sub-10 nm size'. Together they form a unique fingerprint.

Cite this