Photo-induced charge state conversion of Eu{sup 2+} in Ca{sub 2}ZnSi{sub 2}O{sub 7}

Journal Article · Tue Sep 01 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3213360· OSTI ID:21361793

Kamioka, Hayato ^[1]; Hirano, Masahiro ^[2]; Hosono, Hideo ^[3]

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1. Graduate School of Pure and Applied Sciences, University of Tsukuba, Ten-noudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan)
2. Transparent Electro-Active Materials Project, ERATO-SORST, Japan Science and Technology, Bldg. S2-6F East, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)
3. Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)

Eu{sup 2+} doped sorosilicate Ca{sub 2}ZnSi{sub 2}O{sub 7} (melilite) exhibits a broad band emission peaking at approx600 nm(approx2 eV) due to the electric dipole allowed transition of 4f{sup 6}5d{sup 1} to 4f{sup 7} of Eu{sup 2+} by an excitation with blue light (460 nm). Strong O{sup 2-} ligand field with low symmetry due to the layered tetragonal crystallographic structure of the melilite may play a dominant role in lowering the emission band energy to approx2 eV. In addition, line emissions attributable to the transitions from {sup 5}D{sub 0} to {sup 7}F{sub J} of Eu{sup 3+} ions are detected by an excitation with deep UV light with sub-360 nm wavelengths. This is due to the formation of transient Eu{sup 3+} ions via charge transfer from Eu{sup 2+} to the matrix. The lifetime of the transient Eu{sup 3+} ion is found to be 58 ms by a pump-probe measurement, in which UV pulse laser and green continuous wave laser are employed as pump and probe lights, respectively. Based on these results, the energy diagram of Eu{sup 2+} in Ca{sub 2}ZnSi{sub 2}O{sub 7} is proposed.

• OSTI ID: 21361793
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 5; Other Information: DOI: 10.1063/1.3213360; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM SILICATES
CHARGE EXCHANGE
CHARGE STATES
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
DOPED MATERIALS
ELECTRIC DIPOLES
EUROPIUM IONS
EXCITATION
FLUORESCENCE
OXYGEN IONS
PULSES
ULTRAVIOLET RADIATION
ZINC SILICATES
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CHARGED PARTICLES
DIPOLES
ELECTROMAGNETIC RADIATION
EMISSION
ENERGY-LEVEL TRANSITIONS
IONS
LUMINESCENCE
MATERIALS
MULTIPOLES
OXYGEN COMPOUNDS
PHOTON EMISSION
RADIATIONS
SILICATES
SILICON COMPOUNDS
ZINC COMPOUNDS