title: First-Principles Study on Structural, Electronic, and Spectroscopic Properties of γ-Ca2SiO4:Ce(3+) Phosphors.
abstract: In the present work, geometric structures, electronic properties, and 4f → 5d transitions of γ-Ca2SiO4:Ce(3+) phosphors have been investigated by using first-principles calculations. Four categories of typical substitutions (i.e., the doping of the Ce(3+) without the neighboring dopants/defects and with the neighboring VO(••), AlSi', and VCa″) are taken into account to simulate local environments of the Ce(3+) located at two crystallographically different calcium sites in the γ-Ca2SiO4. Density functional theory (DFT) geometry optimization calculations are first performed on the constructed supercells to obtain the information about the local structures and preferred sites for the Ce(3+). On the basis of the optimized crystal structures, the electronic properties of γ-Ca2SiO4:Ce(3+) phosphors are calculated with the Heyd-Scuseria-Ernzerhof screened hybrid functional, and the energies and relative oscillator strengths of the 4f → 5d transitions of the Ce(3+) are derived from the ab initio embedded cluster calculations at the CASSCF/CASPT2/RASSI-SO level. A satisfactory agreement with the available experimental results is thus achieved. Moreover, the relationships between the dopants/defects and the electronic as well as spectroscopic properties of γ-Ca2SiO4:Ce(3+) phosphors have been explored. Such information is vital, not least for the design of Ce(3+)-based phosphors for the white light-emitting diodes (w-LEDs) with excellent performance.
authors.affiliation: †School of Physics and Electronic Engineering, Anqing Normal University, Anqing 246011, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wen
authors.affiliation: ‡Center for Nano Science and Technology, Department of Physics, Anhui Normal University, Wuhu 241000, People's Republic of China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Ning
authors.affiliation: §Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Chang-Kui
authors.initials: CK
authors.lastname: Duan
authors.affiliation: †School of Physics and Electronic Engineering, Anqing Normal University, Anqing 246011, People's Republic of China.
authors.forename: Shengbao
authors.initials: S
authors.lastname: Zhan
authors.affiliation: ‡Center for Nano Science and Technology, Department of Physics, Anhui Normal University, Wuhu 241000, People's Republic of China.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Huang
authors.affiliation: †School of Physics and Electronic Engineering, Anqing Normal University, Anqing 246011, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: §Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Yin