From Structure to Luminescent Properties of B2O3-Bi2O3-SrF2 Glass and Glass-Ceramics Doped with Eu3+ Ions

Abstract

Glass-ceramics with the composition B2O3-Bi2O3-SrF2 were synthesized by the conventional melt-quenching technique and subsequent crystallization of the parental glasses. The temperature at which the ceramization was carried out was selected based on differential scanning calorimetry (DSC) analysis. The structure of the studied materials and the formation of SrF2 nanocrystals were confirmed by the Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques. It was found that the amount of strontium fluoride introduced into the parental borate-bismuth glass has a significant impact on the growth of SrF2 nanocrystals. In particular, the influence of the crystalline SrF2 phase on luminescence intensity and kinetics was studied using Eu2O3-doped samples. An increase in luminescence intensity was observed in the samples in which SrF2 nanocrystals were formed. This is most likely related to the fact that some of the Eu3+ ions were (after annealing of the glass) located in the crystalline structure of strontium fluoride. This was confirmed both by the luminescence lifetime obtained based on the luminescence decay curves and the calculated Judd–Ofelt parameters, Ω2 and Ω4. The results achieved confirm that the glasses and glass-ceramics described in this work could be considered as a new phosphor for light-emitting diodes (LEDs).

Luminescence properties of Eu3+ doped Li2SrSiO4 phosphor

“…It can occur only when Eu 3+ locates at inversion symmetry site in the host [10]. The asymmetric ratio R (luminescence intensity ratio), for Eu 3+ ions can be calculated from the expression R = I ( 5 D0→ 7 F2)/I ( 5 D0→ 7 F1) [11]. From the integral intensities of the emission spectra, the asymmetric ratio is 0.5272 at 253 nm excitation wavelength.…”

A Novel Preparation of Special-Shaped Phosphors-in-Glass by Gel Casting with Isobam for High-Power WLEDs Lighting

“…However, the further development of WLEDs is limited by the traditional phosphor-converter phosphors-in-silicones (PiSs) [7][8][9], because PiSs have problems such as thermal quenching of phosphors and degradation of resin at high temperature. Meanwhile, phosphors-in-glass (PiGs) with good heat dissipation and high heat resistance are a suitable phosphor-converter for high power WLEDs lighting [10][11][12].…”

“…At present, the research of PiGs often focus on three aspects: preparing novel phosphors particles [13][14][15], introducing ions into glass matrix [10,16,17] and reducing sintering temperature [18][19][20]. There are few reports on the effect of changing shape of PiGs on optical properties and heat dissipation.…”

Luminescence mechanisms in the 2V2O5-xLi2O-(98-x)B2O3 glass matrices developed for creation of efficient glass-ceramic materials

“…In many earlier studies, one of the components of the developed glass-ceramics is a boron oxide, B 2 O 3 , because it is one of the best glass forming oxides. Diboron trioxide as a glass former is characterized by a wide glassformation range of concentrations, high transparency, and, moreover, high thermal stability [8][9][10].…”

“…Besides, the addition of some network modi ers to boron oxide, usually alkali oxides, can lead to an increase of coordination number of some of the boron atoms from 3 to 4, changing the properties of borate glass. This phenomenon, known as the "borate anomaly" can improve mechanical properties of the glass [10][11][12]. In the present study we use lithium oxide as the second glass former component of the developed ceramics.…”