Luminescent Properties of RE-doped Mullite (Al6Si2O13) Phosphors(RE = Ce3+, Eu2+, Ce3+-Tb3+, and Eu3+)

• Published in: ECS transactions Vol. 88; no. 1; pp. 237 - 247
• Main Authors: Takahashi, Hirotaka, Matsushima, Yuta
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society, Inc 2019
• ISSN: 1938-5862; 1938-6737; 1938-6737; 1938-5862
• DOI: 10.1149/08801.0237ecst

The luminescent properties of Ce3+, Eu2+, Ce3+-Tb3+, and Eu3+ in the mullite (Al6Si2O13) host were investigated for realization of full colors phosphors with a single type host. Ce3+ and Eu2+ in mullite showed blue photoluminescence (PL), whereas green and red emission were obtained in the Ce3+-Tb3+ and Eu3+ doped mullite. The prepared phosphors had the excitation band around 300 nm. The PL intensity at 200 °C kept 70 % of the initial intensity at room temperature.The X-ray diffraction study indicated the incorporation of the rare-earth (RE) ions in the mullite lattice without forming secondary phases, although it was not probable that the RE ions substituted for Al3+ and Si4+ because of the significant difference in ionic size. The bond-valence-sum and the differential electron density map analysis indicated that the doped RE ions occupied the stoichiometrically-introduced vacant oxygen site, which was the site for oxygen originally. The amphoteric nature of the oxygen site in mullite was proposed.