Spectroscopic properties of Pr3+-doped Titania-Silicate glass ceramic for photonic applications.

Silicate-Titania (SiTi) glass-ceramics doped with Pr3+ (0.6, 1.6, 2.4 and 3.6 mol%) ions were prepared by sol-gel technique. The materials were characterized by powder XRD, FTIR, TEM, EDX, Optical absorption and Photoluminescence spectroscopy. The identification of non-bridging oxygen (NBO) formation and the removal of OH groups are validated through analysis of the FTIR spectra. Additionally, measurements using XRD and TEM showed that the samples contain nano-sized crystallites. The three phenomenological Judd–Ofelt (J–O) intensity parameters Ω 2 , Ω 4 , and Ω 6 were obtained and used to analyze different radiative characteristics for the fluorescence levels of Pr3+ in the glass ceramic, including radiative lifetime, branching ratio, radiative transition probability and stimulated emission cross-section. Several emissions were observed in the visible region, among which the 1D 2 →3H 4 in the orange-red region is the most intense. All of these reported branching ratios, stimulated emission cross-sections, and visible emission spectra point to the possibility of employing them as red region lasers. The CIE chromaticity coordinates from all of the emission spectra were also assessed to determine if these materials are suitable for orange-red phosphors. According to CIE chromaticity investigations, 1.6 mol% of Pr3+ ion concentration is ideal for SiTiPr glass-ceramic for use as red phosphors and possibly red lasers. • SiO 2 –TiO 2 glass ceramics doped with Pr3+ are synthesized by sol-gel technique. • TiO 2 nanocrystals of size around 10–20 nm are formed. • Judd-Ofelt parameters and radiative parameters are calculated. • Strong emissions in the orange-red region are observed under blue excitation. • Cross-relaxation reduces luminescence at high Pr3+ concentration. [ABSTRACT FROM AUTHOR]