Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8948511 | Ceramics International | 2018 | 39 Pages |
Abstract
Orange-red light-emitting Sm3+-doped cerium oxide (CeO2) ceramic powder with various concentrations of Sm3+ ions was prepared through a sol-gel process. X-ray diffraction and Rietveld analysis confirmed the formation of a purely cubic structure with a space group of Fm3Ì
m. The lattice parameters and unit cell volumes of the CeO2:Sm3+ powder increased with the concentration of Sm3+ ions. The energy-dispersive X-ray spectra and corresponding mapping images confirmed the elemental composition and adequate dispersion of all elements in the CeO2:Sm3+ powder. A broad excitation band at approximately 365ânm was observed in the excitation spectra of CeO2:Sm3+ phosphors owing to the charge transfer transition from O 2p to Ce 4f orbitals. The Sm3+ doped CeO2 phosphors emitted sharp luminescence with a main peak at 615ânm under excitation at 360ânm. The spectral analysis revealed that the CeO2:Sm3+ phosphors exhibited strong orange-red emission. Concentration quenching was observed in the CeO2:Sm3+ phosphors with 0.5âmol% of critical concentration of Sm3+ ions due to dipole dipole interaction of two nearest Sm3+ ions. The quantum efficiency was observed as high as 58%. The thermal stability of the present materials was estimated with the evaluation of activation energy as 0.31âeV. The broad excitation band and sharp orange-red emission indicated the potential use of CeO2:Sm3+ phosphors for white light-emitting diodes.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Anil Kumar Pal, Sudipta Som, Chung-Hsin Lu,