tailieunhanh - Optical properties of Eu3+ ions doped aluminosilicate glass

Eu3+ -doped aluminosilicate (AlSi) glass with the concentrations of wt % was prepared by Solgel method. Optical excitation and emission spectra of Eu3+ ions have been investigated. | Phan Văn Độ và Đtg Tạp chí KHOA HỌC & CÔNG NGHỆ 190(14): 85 - 90 OPTICAL PROPERTIES OF Eu3+ IONS DOPED ALUMINOSILICATE GLASS Phan Van Do1, Nguyen Xuan Ca2 1 Thuyloi University, 2University of Science - TNU ABSTRACT Eu3+ -doped aluminosilicate (AlSi) glass with the concentrations of wt % was prepared by Solgel method. Optical excitation and emission spectra of Eu3+ ions have been investigated. The phonon sideband (PSB) associated with the 7F0-5D2 excitation transition is used to determine the electron–phonon coupling constant and the local structure of the local environment around Eu3+ ions. The luminescence intensity ratio of the 5D0-7F2 to 5D0-7F1 transition has been calculated to estimate the local site symmetry around the Eu3+ ions. The Judd–Ofelt (JO) intensity parameters Ωλ (λ=2, 4, 6) are calculated from the emission spectra and are used to estimate the transition probability (A), branching ratios (β), the stimulated emission cross-sections (σλp) for the excited levels 5D0 of the Eu3+ ions. Key word: Sol-gel method, aluminosilicate glass, Judd- Ofelt theory INTRODUCTION* Rare earth (RE) doped glasses have been attracted the attention of scientists due to their wide applications in many optical devices like lasers, light converters, sensors, high-density memories and optical amplifiers [1, 2]. Among the RE3+ ions used to optically activate materials, the Eu3+ ions are mostly chosen due to Eu3+ ions emit narrow-band, almost monochromatic light and have long lifetime of the optically active states [2, 3]. Further, the structure and the relative intensities of the optical transitions in Eu3+ ion strongly depend on the its local environment, so this ion is used as a probe to study the point group symmetry of the Eu3+ site and sometimes also information on the coordination polyhedron [1-3]. As for the hosts, alumina is a good network modifier for dispersing RE3+ ions in silica gel and silicate glass matrices, in which RE3+ ions were preferably partitioned