Yb3+/Er3+ codoped β-NaYF4 microrods: Synthesis and tuning of multicolor upconversion

Influence of SiO2 layer on the plasmon quenched upconversion luminescence emission of core-shell NaYF4:Yb,Er@SiO2@Ag nanocomposites

“…It is true that a stronger green emission than red emission under lower excitation power(30 mW) was observed, and the red emission became stronger than the green one under high excitation power. This phenomenon has been involved in many literatures [35,36]. The reason is that under high excitation power, the cross-relaxation derived from Er 3+ , such as Er: 4 S 3/2 +Er: 4 I 13/2 →Er: 4 F 9/2 +Er: 4 I 11/2 , happens.…”

Hydrothermal synthesis and up-conversion luminescence properties of NaYF4:Yb3+,Tm3+ phosphors

“…However, the content extends from 0.4% to 1.0%, while the luminescence intensity of the synthesized products reduces drastically. We can say that the introduction of an elevated amount of codopants (Tm 3þ ) in the NaYF 4 host lattice will decrease the distance of codopant ions and thus facilitate energy transfer between Tm 3þ ions [25]. Note that the probability of collision between Tm 3þ ions increases, resulting in the fluorescence quenching phenomenon and the luminescence intensity decreases.…”

Controlled hydrothermal growth and tunable luminescence properties of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals

“…The phase purity and composition of the products prepared under various pH values (3,5,7, and 10) were first examined by XRD, as shown in Fig. 1.…”

“…Rare earth fluoride compounds with the formula like NaREF 4 (RE = rare earth), especially hexagonal phase NaYF 4 , possessing a high refractive index and low phonon energy, have become a new focus of research [6][7][8]. Most of applications make great demands on different morphologies and sizes of bNaYF 4 crystals, also the UC luminescence properties of b-NaYF 4 crystals doped with different lanthanide ions or ion pairs are directly related to their sizes and shapes [9][10][11].…”