Synthesis and upconversion luminescence of YF3:Yb3+ Tm3+ and TiO2-coated YF3:Yb3+, Tm3+ microcrystals.
YF3:Yb3+, Tm3+ microcrystals were prepared by a microemulsion method. The microcrystals were coated with TiO2 by hydrolysis of titanium n-butoxide (TBOT). Transform electron microscopy and X-ray diffraction were used to characterize the core/shell materials. The results indicated that the low TBOT/YF3 molar ratio was favorable to preparing the uniform TiO2 coatings. The upconversion luminescence properties of YF3:Yb3+, Tm3+ and TiO2-coated YF3:Yb3+, Tm3+ microcrystals were studied under 980-nm excitation. The 1I6 --> 3H6, 1I6 --> 3F4, 1D2 --> 3H6, 1D2 --> 3F4, 1G4 --> 3H6, and 1G4 --> 3F4 emissions were observed. The upconversion mechanisms were discussed in detail.
Zhang
Daisheng
D
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, PR China.
Qin
Weiping
W
Wang
Guofeng
G
Wei
Guodong
G
Wang
Lili
L
Zhu
Peifen
P
Kim
Ryongjin
R
Ding
Fuheng
F
Zheng
Kezhi
K
Liu
Ning
N