English  |  正體中文  |  简体中文  |  Items with full text/Total items : 62378/95055 (66%)
Visitors : 2302058      Online Users : 17
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version
    Please use this identifier to cite or link to this item: https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/120497

    Title: Correlation among photoluminescence and the electronic and atomic structures of Sr2SiO4:xEu3+ phosphors: X-ray absorption and emission studies
    Authors: Zheng, Shi-Yan;Chiou, Jau-Wern;Li, Yueh-Han;Yang, Cheng-Fu;Ray, Sekhar Chandra;Chen, Kuan-Hung;Chang, Chun-Yu;Shelke, Abhijeet R.;Wang, Hsiao-Tsu;Yeh, Ping-Hung;Lai, Chun-Yen;Hsieh, Shang-Hsien;Pao, Chih-Wen;Chen, Jeng-Lung;Lee, Jyh-Fu;Tsai, Hung-Ming;Hua, Huang-Wen FuvChih-Yu;Lin, Hong-Ji;Chen, Chien-Te;Pong, W. F.
    Keywords: Materials science;Physics
    Date: 2020-07-29
    Issue Date: 2021-04-15 12:11:32 (UTC+8)
    Abstract: A series of Eu3+-activated strontium silicate phosphors, Sr2SiO4:xEu3+ (SSO:xEu3+, x = 1.0, 2.0 and 5.0%), were synthesized by a sol–gel method, and their crystalline structures, photoluminescence (PL) behaviors, electronic/atomic structures and bandgap properties were studied. The correlation among these characteristics was further established. X-ray powder diffraction analysis revealed the formation of mixed orthorhombic α'-SSO and monoclinic β-SSO phases of the SSO:xEu3+ phosphors. When SSO:xEu3+ phosphors are excited under ultraviolet (UV) light (λ = 250 nm, ~ 4.96 eV), they emit yellow (~ 590 nm), orange (~ 613 nm) and red (~ 652 and 703 nm) PL bands. These PL emissions typically correspond to 4f–4f electronic transitions that involve the multiple excited 5D0 → 7FJ levels (J = 1, 2, 3 and 4) of Eu3+ activators in the host matrix. This mechanism of PL in the SSO:xEu3+ phosphors is strongly related to the local electronic/atomic structures of the Eu3+–O2− associations and the bandgap of the host lattice, as verified by Sr K-edge and Eu L3-edge X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure, O K-edge XANES and Kα X-ray emission spectroscopy. In the synthesis of SSO:xEu3+ phosphors, interstitial Eu2O3-like structures are observed in the host matrix that act as donors, providing electrons that are nonradiatively transferred from the Eu 5d and/or O 2p–Eu 4f/5d states (mostly the O 2p–Eu 5d states) to the 5D0 levels, facilitating the recombination of electrons that have transitioned from the 5D0 level to the 7FJ level in the bandgap. This mechanism is primarily responsible for the enhancement of PL emissions in the SSO:xEu3+ phosphors. This PL-related behavior indicates that SSO:xEu3+ phosphors are good light-conversion phosphor candidates for use in near-UV chips and can be very effective in UV-based light-emitting diodes.
    Relation: Scientific Reports 10(1), 12725
    DOI: 10.1038/s41598-020-69428-7
    Appears in Collections:[Graduate Institute & Department of Physics] Journal Article

    Files in This Item:

    File Description SizeFormat

    All items in 機構典藏 are protected by copyright, with all rights reserved.

    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - Feedback