Eu3+-site occupations and peculiar reddish orange luminescence in aluminates Sr3RAl2O7.5:Eu3+ (R=Y, Lu)

• Published in: Journal of luminescence Vol. 154; pp. 99 - 105
• Main Authors: Zhang, Wansong, Lin, Chundan, Huang, Yanlin, Cai, Peiqing, Kim, Sun Il, Seo, Hyo Jin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2014; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Eu3+ ions; Exact sciences and technology; Inorganic compounds; Materials science; Materials synthesis; materials processing; Optical materials and properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Point defects; Site-selective excitation spectroscopy; Site-selective excitation spectroscopy; Optical materials and properties; Point defects; Inorganic compounds; Eu3+ ions; Energy levels; Doping; Luminescence; Photoluminescence; Dye lasers; Stark effect; XRD; Selective excitation; Eu; Calcium nitride; Emission spectra; Crystallographic site; Illumination; Excitation spectrum; ions; Charge transfer; Sol-gel process; Scanning electron microscopy; Organic dye; Quantum yield; Luminescence decay; Ultraviolet radiation; Phosphors; X radiation; Chromaticity; Optical materials; Energy transfer
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2014.04.013

A novel reddish orange-emitting phosphor of Eu3+-doped aluminate Sr3RAl2O7.5 (R=Lu, Y) was successfully synthesized by wet-chemistry sol–gel method. The samples were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The luminescence properties such as photoluminescence excitation and emission spectra, decay curves, CIE color coordinates and luminescence quantum efficiency were investigated. This phosphor can be efficiently excited by UV and near-UV light and exhibits a bright reddish orange luminescence with the abnormally strongest 5D0→7F0 transition. Two distinct Eu3+ sites can be observed on the emission spectra under the excitation of UV light (excitation at charge transfer band of Eu3+ ions) or dye laser in the 5D0→7F0 wavelength region (selective excitation into each site). The site-selective luminescence decay curves have been investigated in the 5D0→7F0 region of each Eu3+ site by using a pulsed, tunable, and narrowband dye laser. Each Eu3+ site presents the distinct luminescence lifetime with different rise time. The Stark energy levels of two Eu3+ sites were assigned from the site-selective emission spectra. The energy transfer can happen between the closely neighbored Eu3+ sites in Sr3RAl2O7.5 (R=Lu, Y). The luminescence mechanism responsible for the abnormally strong 5D0→7F0 transition was discussed. •A novel phosphor of Eu3+-doped Sr3RAl2O7.5 (R=Lu, Y) was synthesized with fine crystalline particles.•It can be efficiently excited by UV- or near UV light and presents bright reddish-orange color.•Eu3+-doped Sr3RAl2O7.5 (R=Lu, Y) presents the strongest 5D0→7F0 emission lines.•Two distinct Eu3+ sites can be observed in the lattice, one is at 580.6nm (17,223cm−1) and another at 581.9nm (17,185cm−1).