title: Design, Preparation, and Characterization of a Novel Red Long-Persistent Perovskite Phosphor: Ca3Ti2O7:Pr3+.
abstract: Currently, the development of efficient red-emitting persistent phosphor is still an ongoing challenge. Herein, a novel red-emitting LPL phosphor Ca3Ti2O7:Pr(3+) is successfully prepared by a high-temperature solid-state method. XRD Rietveld refinement analyses demonstrate the high phase purity of the sample which crystallizes in an orthorhombic Ccm21 space group with lattice parameters of a = 5.7702(5) Å, b = 19.4829(7) Å, and c = 5.1214(2) Å. Electronic structure of the host matrix is analyzed by the first-principle calculation using CASTEP code. The calculation results show that Ca3Ti2O7 has a direct band gap with CB and VB mainly composed of the Ti-3d and O-2p states, respectively. On the basis of the DR spectrum, the band gap is determined to be 3.6 eV. It is demonstrated that the 612 nm red-emitting persistent luminescence of Ca3Ti2O7:Pr(3+) can be either activated by Ti(4+)-O(2-) → Ti(3+)-O(-) host absorption and Pr(3+)-O-Ti(4+) → Pr(4+)-O-Ti(3+) IVCT in the UV region, or Pr(3+):(3)H4 → (3)PJ transition in the blue region. The red afterglow can last for ∼ 5 min observed by the naked eyes in the dark after ceasing the irradiation source. On the basis of the TL analyses, the trap is found exponentially distributed in the host with the depth of 0.69-0.92 eV. Finally, a possible LPL mechanism for Ca3Ti2O7:Pr(3+) is proposed.
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.|Fujian Provincial Key Laboratory of Nanomaterials , Fuzhou, Fujian 350002, P. R. China.
authors.forename: Hang
authors.initials: H
authors.lastname: Lin
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.|Fujian Provincial Key Laboratory of Nanomaterials , Fuzhou, Fujian 350002, P. R. China.
authors.forename: Ju
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.
authors.forename: Zebin
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.|Fujian Provincial Key Laboratory of Nanomaterials , Fuzhou, Fujian 350002, P. R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Huang
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Fuzhou, Fujian 350002, P. R. China.|Fujian Provincial Key Laboratory of Nanomaterials , Fuzhou, Fujian 350002, P. R. China.
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Wang