Ultraviolet upconversion fluorescence from 6D(J) of Gd3+ induced by 980 nm excitation.
Ultraviolet upconversion emissions of 246.2 and 252.8 nm from (6)D(J) levels of Gd(3+) ions were observed in GdF(3): 10% Yb(3+), 0.7% Tm(3+) nanocrystals under 980 nm excitation from a laser diode. The (6)D(J) levels of Gd(3+) ions can be efficiently populated by energy transfer processes of Yb-->Tm-->Gd and Yb-->Gd. A six-photon upconversion process was confirmed by the dependence of 252.8 nm emission intensity on the pumping power. The upconversion mechanism in the six-photon process was discussed based on excited state absorption of Gd(3+) ions, cross relaxation energy transfer between two excited Gd(3+) ions, and energy transfer between Gd(3+) and Yb(3+) or Tm(3+) ions.
Qin
Weiping
W
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China. wpqin@jlu.edu.cn
Cao
Chunyan
C
Wang
Lili
L
Zhang
Jisen
J
Zhang
Daisheng
D
Zheng
Kezhi
K
Wang
Yan
Y
Wei
Guodong
G
Wang
Guofeng
G
Zhu
Peifen
P
Kim
Ryongjin
R