Layered rare-earth hydroxide and oxide nanoplates of the Y/Tb/Eu system: phase-controlled processing, structure characterization and color-tunable photoluminescence via selective excitation and efficient energy transfer

Xiaoli Wu; Ji-Guang Li; Jinkai Li; Qi Zhu; Xiaodong Li; Xudong Sun; Yoshio Sakka

doi:10.1088/1468-6996/14/1/015006

Layered rare-earth hydroxide and oxide nanoplates of the Y/Tb/Eu system: phase-controlled processing, structure characterization and color-tunable photoluminescence via selective excitation and efficient energy transfer

Sci Technol Adv Mater. 2013 Feb 21;14(1):015006. doi: 10.1088/1468-6996/14/1/015006. eCollection 2013 Feb.

Authors

Xiaoli Wu¹, Ji-Guang Li¹, Jinkai Li², Qi Zhu², Xiaodong Li², Xudong Sun², Yoshio Sakka³

Affiliations

¹ Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China; Advanced Materials Processing Unit, National Institute for Materials Science, Sengen 1-2-1, Tsukuba, Ibaraki 305-0047, Japan.
² Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning 110004, China.
³ Advanced Materials Processing Unit, National Institute for Materials Science, Sengen 1-2-1, Tsukuba, Ibaraki 305-0047, Japan.

Abstract

Well-crystallized (Y_0.97-x Tb_0.03Eu _x )₂(OH)₅NO₃·nH₂O (x = 0-0.03) layered rare-earth hydroxide (LRH) nanoflakes of a pure high-hydration phase have been produced by autoclaving from the nitrate/NH₄OH reaction system under the optimized conditions of 100 °C and pH ∼7.0. The flakes were then converted into (Y_0.97-x Tb_0.03Eu _x )₂O₃ phosphor nanoplates with color-tunable photoluminescence. Detailed structural characterizations confirmed that LRH solid solutions contained NO₃^- anions intercalated between the layers. Characteristic Tb³⁺ and Eu³⁺ emissions were detected in the ternary LRHs by selectively exciting the two types of activators, and the energy transfer from Tb³⁺ to Eu³⁺ was observed. Annealing the LRHs at 1100 °C produced cubic-lattice (Y_0.97-x Tb_0.03Eu _x )₂O₃ solid-solution nanoplates with exposed 222 facets. Multicolor, intensity-adjustable luminescence was attained by varying the excitation wavelength from ∼249 nm (the charge transfer excitation band of Eu³⁺) to 278 nm (the 4f⁸-4f⁷5d¹ transition of Tb³⁺). Unitizing the efficient Tb³⁺ to Eu³⁺ energy transfer, the emission color of (Y_0.97-x Tb_0.03Eu _x )₂O₃ was tuned from approximately green to yellowish-orange by varying the Eu³⁺/Tb³⁺ ratio. At the optimal Eu³⁺ content of x = 0.01, the efficiency of energy transfer was ∼91% and the transfer mechanism was suggested to be electric multipole interactions. The phosphor nanoplates developed in this work may be incorporated in luminescent films and find various lighting and display applications.

Keywords: 10.11; 20.03; 20.09; color-tunable luminescence; energy transfer; layered rare-earth hydroxide; solid solution.

Publication types

Review