NIR to VUV: Seven-Photon Upconversion Emissions from Gd(3+) Ions in Fluoride Nanocrystals.
Here we show that a near-infrared (NIR) diode laser is capable of generating vacuum ultraviolet (VUV) emissions in fluoride nanocrystals through photon upconversion (UC) processes. By using Yb(3+) and Tm(3+) as sensitizers, we successfully obtained the VUV photons with the energy exceeding 6 eV in YF3: Yb, Tm, and Gd nanocrystals. The seven photon UC fluorescence from the (6)GJ → (8)S7/2 transitions of Gd(3+) ions and the possible VUV UC mechanism were reported along with the calculation of the branching ratio under different pumping power excitation. Practically, it offers a promising solution for VUV light generation without cryogens and expensive instrumentations. Fundamentally, the extremely high-order UC processes will intrigue great interest in exploring unusual high-energy radiative transitions in rare earth ions.
†State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Kezhi
K
Zheng
†State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Weiping
W
Qin
‡School of Materials Science and Engineering, Xiamen University of Technology, No.600 Ligong Road, Jimei District, Xiamen 361024, China.
Chunyan
C
Cao
†State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Dan
D
Zhao
†State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Lili
L
Wang
gadolinium ion; high order; small size effect; upconversion luminescence; vacuum ultraviolet