title: Unconventional Luminescent Centers in Metastable Phases Created by Topochemical Reduction Reactions.
abstract: A low-temperature topochemical reduction strategy is used herein to prepare unconventional phosphors with luminescence covering the biological and/or telecommunications optical windows. This approach is demonstrated by using Bi(III)-doped Y2O3 (Y(2-x)Bi(x)O3) as a model system. Experimental results suggest that topochemical treatment of Y(2-x)Bi(x)O3 using CaH2 creates randomly distributed oxygen vacancies in the matrix, resulting in the change of the oxidation states of Bi to lower oxidation states. The change of the Bi coordination environments from the [BiO6] octahedra in Y(2-x)Bi(x)O3 to the oxygen-deficient [BiO(6-z)] polyhedra in reduced phases leads to a shift of the emission maximum from the visible to the near-infrared region. The generality of this approach was further demonstrated with other phosphors. Our findings suggest that this strategy can be used to explore Bi-doped or other classes of luminescent systems, thus opening up new avenues to develop novel optical materials.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P.R. China.
authors.forename: Bo-Mei
authors.initials: BM
authors.lastname: Liu
authors.affiliation: Department of Physical Science, Hiroshima University, Higashihiroshima, Hiroshima, 739-8526, Japan.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai, 201418, P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Physical Science, Hiroshima University, Higashihiroshima, Hiroshima, 739-8526, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kuroiwa
authors.affiliation: Department of Physical Science, Hiroshima University, Higashihiroshima, Hiroshima, 739-8526, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Moriyoshi
authors.affiliation: Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, P.R. China.
authors.forename: Hui-Mei
authors.initials: HM
authors.lastname: Yu
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, 710049, P.R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Zheng
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201204, P.R. China.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Li
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, 710049, P.R. China.
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai, 201418, P.R. China.
authors.forename: Yong-Zheng
authors.initials: YZ
authors.lastname: Fang
authors.affiliation: School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai, 201418, P.R. China.
authors.forename: Jing-Shan
authors.initials: JS
authors.lastname: Hou
authors.affiliation: National Institute for Material Sciences (NIMS), 1-2-1 Sengen, Tsukuba-city, Ibaraki, 305-0047, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Matsushita
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P.R. China. timothyhsun@gmail.com.
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Sun
keywords: bismuth; luminescence; phosphors; reduction; topochemistry