Abstract
Ytterbium (Yb3+) doped aluminium oxide (Al2O3) powder phosphor was successfully synthesized by solution combustion method. The structure, vibrational bending modes, particle morphology, chemical composition, and photoluminescent properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and photoluminescent (PL) spectroscopy respectively. The XRD patterns confirmed that Al2O3 crystallized in its stable polymorphic hexagonal α-Al2O3 phase with space group R3c. The average crystallite size estimated from Debye-Scherrer equation was 29 nm. The FTIR confirmed the Al-O vibrations associated with α-Al2O3 and the Yb-O vibrations. The SEM data showed that the powders were made up of particles with different shapes but well defined boundaries. Furthermore, the SEM images show that the Yb3+ ions resided on the grain boundaries. When the powders were excited using a 325 nm He-Cd laser, the emission was observed in the near infrared (NIR) at 975 nm due to the 2F5/2→2F7/2 transition of Yb3+. However, the bluish green emission with a maxima at ~ 480 nm was observed as a result of cooperative luminescence of Yb3+ when the powders were excited in the NIR with an excitation wavelength of 980 nm. Cooperative energy transfer (CET) mechanism producing NIR emission for the 325 nm laser excited Al2O3:Yb3+ powders is presented and discussed.
Original language | English |
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Pages (from-to) | 174-181 |
Number of pages | 8 |
Journal | Ceramics International |
Volume | 43 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jan 2017 |
Externally published | Yes |
Keywords
- Alumina
- Cooperative luminescence
- Phosphors
- Photoluminescence
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry