Abstract
A series of CaMgB2O5 phosphors co-doped with Sm3+ and alkali metal ions (Li+, Na+ and K+) were prepared by combustion method. The crystal structure of the phosphors was investigated by using X-ray diffraction (XRD) after annealing the phosphor at 900 °C. The crystal structure belongs to the monoclinic phase of CaMgB2O5with space group P21/b. FTIR spectra shows the absorption bands for various structural units of borate mainly BO3 triangles and lattice vibrations of Ca-O and Mg-O. The luminescence and spectral properties were studied by photoluminescence (PL) and diffuse reflectance (DR) spectroscopy. The result shows that under 400 nm excitation, the phosphor shows characteristic emission of Sm3+ ion with the main orange-red peak at 600 nm. The optimum dopant concentration of Sm3+ ion was 1.5 mol% and the main mechanism for concentration quenching was dipole-dipole (d-d) interaction determined by using Dexter's theory. As a charge compensator, alkali metal ions (Li+, Na+ and K+) were incorporated into the host lattice of CaMgB2O5: Sm3+ phosphors, which enhanced the PL intensities. The calculated CIE coordinates (0.59, 0.41) under 400 nm excitation were found to be in the orange-red region of the spectrum.
Original language | English |
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Pages (from-to) | 9-16 |
Number of pages | 8 |
Journal | Nano-Structures and Nano-Objects |
Volume | 3 |
DOIs | |
Publication status | Published - 1 Oct 2015 |
Externally published | Yes |
Keywords
- Alkali metal ions
- Borates
- Charge compensation
- Photoluminescence
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- General Materials Science
- Condensed Matter Physics
- Physical and Theoretical Chemistry