Sol–gel based YAG : Tb3+ or Eu3+ phosphors for application in lighting sources

• Published in: Journal of physics. D, Applied physics Vol. 38; no. 17; pp. 3251 - 3260
• Main Authors: Potdevin, A, Chadeyron, G, Boyer, D, Caillier, B, Mahiou, R
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bristol IOP Publishing 07.09.2005; Institute of Physics
• Subjects: Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Engineering Sciences; Exact sciences and technology; Materials science; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other materials; Other solid inorganic materials; Photoluminescence; Physics; Plasma Physics; Plasmas; Specific materials; Terbium additions; Atomic force microscopy; Scanning electron microscopy; Spray coatings; Laser induced fluorescence; Luminescence; Doped materials; XRD; Experimental study; Yttrium Aluminates; Thin films; Nanoparticles; Europium additions; Optical properties; Radiation sources; Europium III; Microstructure; Terbium III; Sol-gel process; YAG
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/38/17/S29

Luminescent Y3Al5O12 : Eu3+ (YAG : Eu3+) and Y3Al5O12 : Tb3+ (YAG : Tb3+) powders with nanometre and micrometre-sized particles and films have been successfully synthesized by sol-gel route from alkoxide precursors. Advanced YAG coatings were achieved by spray and dip-coating methods, giving rise to different structural and optical properties. High temperature x-ray diffraction, x-ray powder diffraction, scanning electron microscopy and atomic force microscopy were used to investigate the materials structure and morphology. Pure polycrystalline YAG powder was obtained from 900DGC. Laser induced luminescence spectra as well as luminescence decays of Tb3+ and Eu3+ ions were recorded. This study showed, undoubtedly, the spectral features of an Eu3+ emitting centre embedded in a unique site of D2 symmetry. Furthermore, the well-known cross-relaxation phenomenon was observed for Tb3+. Decay times were found to be exponential and shorter than 5 ms for both Eu3+ and Tb3+ activators. Finally, the spectroscopic properties of YAG : Tb3+ powders under vacuum ultra violet excitation were analysed and encouraging results were obtained regarding luminescence efficiency and time constants.