Electronic structure and photoluminescence properties of Eu{sup 2+}-activated Ca{sub 2}BN{sub 2}F

Journal Article · Tue Dec 15 00:00:00 EST 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.09.028· OSTI ID:21372425

Fang, C M ^[1]; Fang, Y ^[2]; Delsing, A C.A. ^[3]; With, G de ^[3]; Hintzen, H T ^[3]

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1. Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft (Netherlands)
2. College of Materials Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)
3. Laboratory of Materials and Interface Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven (Netherlands)

The electronic structure of undoped and luminescence properties of Eu{sup 2+}-doped Ca{sub 2}BN{sub 2}F have been investigated. First-principles calculations for Ca{sub 2}BN{sub 2}F show that the valence band is mainly composed of F and N 2p, B 2s and 2p orbitals, while the Ca 4s and 3d are almost empty, indicating that Ca{sub 2}BN{sub 2}F is a very ionic compound. The valence band close to the Fermi level is dominated by the N 2p states, and the bottom of the conduction band is determined by the Ca 3d and N/B 3s orbitals. The direct energy gap is calculated to be about 3.1 eV, in fair agreement with the experimental data of {approx}3.6 eV derived from the diffuse reflection spectrum. Due to the high degree of ionic bonding of the coordinations of Eu with (N, F) on the Ca sites, Ca{sub 2}BN{sub 2}F:Eu{sup 2+} shows strong blue emission with a maximum at about 420 nm upon UV excitation in the absorption range of 330-400 nm. - Graphical abstract: Diffuse reflection spectrum, excitation and emission spectra of Ca{sub 2}BN{sub 2}F:Eu{sup 2+}, showing that only the ionic Eu{sup 2+} center offers deep blue emission at about 422 nm under excitation at 339 nm.

• OSTI ID: 21372425
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 12; Other Information: DOI: 10.1016/j.jssc.2009.09.028; PII: S0022-4596(09)00463-0; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON NITRIDES
CALCIUM COMPOUNDS
DOPED MATERIALS
ELECTRONIC STRUCTURE
EMISSION SPECTRA
EUROPIUM IONS
EV RANGE 01-10
FERMI LEVEL
FLUORIDES
PHOTOLUMINESCENCE
VALENCE
ALKALINE EARTH METAL COMPOUNDS
BORON COMPOUNDS
CHARGED PARTICLES
EMISSION
ENERGY LEVELS
ENERGY RANGE
EV RANGE
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
IONS
LUMINESCENCE
MATERIALS
NITRIDES
NITROGEN COMPOUNDS
PHOTON EMISSION
PNICTIDES
SPECTRA