Doped Bismuth Borate Glasses Research Articles

Optical Characteristics of Chromium Oxide Doped Bismuth Borate Glasses

Optical Characteristics of Chromium Oxide Doped Bismuth Borate Glasses

Optical Spectroscopy and Excited-State Dynamics of Eu3+ -Doped Bismuth Borate Glasses Containing CuO.

Bismuth borate glasses containing phosphors and luminescent rare-earths are of interest for applications in light-emitting devices. Herein, the influence of CuO impurities on red-emitting Eu3+ -doped bismuth borate glasses of the 25Bi2 O3 -15BaO-10Li2 O-50B2 O3 type was investigated by various spectroscopic methods. The glasses were prepared by the melt-quench technique and characterized by X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, UV/Vis optical absorption (OA), and photoluminescence (PL) spectroscopy including decay kinetics assessment. The XRD data confirmed the amorphous nature of the glasses whereas FT-IR spectra indicated the basic structural features of trigonal BO3 units and BO4 tetrahedra. The OA analysis showed that addition of CuO up to 0.5 mol% results in significant growth of the visible Cu2+ absorption band around 715 nm, with slight decrease in the optical band gap energies assessed through Tauc plots. A drastic PL quenching of Eu3+ ions emission was evidenced concurring with the detrimental effect of Cu2+ . The assessment of the Eu3+ emission decay curves revealed significant lifetime decrease of the 5 D0 emitting state with increasing CuO concentration. An analysis of quenching constants was finally performed comparing results from integrated PL data with the emission decay rates. It is argued that the bismuth borate glass system supports an effective Eu3+ →Cu2+ energy transfer (more so than phosphates) in connection with a strong spectral overlap between Eu3+ emission and Cu2+ absorption.

Luminescence characteristics of Nd3+ doped bismuth borate glasses for photonic applications

Nd3+ doped BBZPA glasses were prepared by conventional melt quenching method and used to study their structural, absorption, emission and decay properties. From XRD, amorphous nature of the undoped glass has been confirmed. The J-O intensity parameters Ωλ (λ = 2, 4, 6) and the various radiative parameters were calculated from J-O analysis. From the emission spectra, it is observed that, the laser transition 4F3/2 → 4I11/2 at 1059 nm is more intense transition. The decay curves for prepared glasses exhibited single exponential decay. The above results suggest that Nd3+ doped BBZPA glasses could be suitable for photonic applications.

Investigations on structural and radiation shielding properties of Er3+ doped zinc bismuth borate glasses

Novel optical glasses 10ZnO-5Na2CO3-10Bi2O3-(75-x)B2O3-xEr2O3 with x = (0, 0.1, 0.3, 0.5, 0.7, 1.0) mol%, were synthesized by melt quench technique and characterized through XRD, EDAX, optical and luminescent properties, before and after irradiating them with high energy (1.3 MeV) gamma rays. Moreover, the gamma photons attenuation characterizations for the samples under study were studied. The mass attenuation coefficients for the selected glasses were affected with the addition of Er2O3. Based on the findings from the mass attenuation coefficients, ZNBBEr-5 has better photon attenuation features in comparison with the other samples. Also, arising the Er2O3 content in the glasses, led to increase the effective atomic number. The mean free path for the prepared samples were compared with some shieling glasses. Shielding performance of the present glass samples against gamma radiation reveals pair production is prominent at 1.3 MeV. UV-VIS–NIR absorption edge was red shifted after gamma irradiation indicating the formation of electron/absorption centers in the glass matrix. Thermally stimulated Luminescence (TL) spectroscopy technique showed five electron trap centers at 445K, 491K, 545K, 590K, 620K with acceptable FOM [< 5%] values. The number of overlapping peaks and their trapping parameters like kinetic order, activation energy, peak temperature, frequency factor and half life were determined using the Computerized Glow Curve Deconvolution (CGCD). Linear behaviour obtained through the dose response of the glass (5 kGy–50 kGy) proved their suitability for dosimetric application in the food irradiation zones and in red LEDs (<50 kGy).

Structural, optical and thermal properties of nickel doped bismuth borate glasses

Nickel doped Bismuth Borate glasses with composition (70B2O3-(30-x)Bi2O3-xNiO) where x = 0,0.5,1.0,1.5,2.0 (wt%) have been synthesized by conventional melt quenching technique. X-Ray Diffractograms have confirmed the amorphous nature of the prepared glasses. The calculated physical parameters such as density, molar volume, average boron‑boron separation, ion concentration and inter ionic distance provided the information about the structural stability of glass samples. DTA and OPD confirmed the decrease in glass transition temperature (Tg) with increase in Ni content. The FTIR and Raman studies clearly revealed that the glass network mainly comprises of [BiO3], [BiO6], [BO3] and [BO4] units. It is also observed that the introduction of dopant (Ni) and modifier (Bi) leads to the conversion of [BO3] trigonal units into the [BO4] tetragonal units due to the increase in non-bridging oxygen atoms which results in the increase of degree of disorder in the glass network. The optical absorption measurements (UV) carried out for well polished glass samples show a decrease in optical band gap with the increase in Ni doping. This observation was further supported by the urbach energy calculations and metallization criterion of the prepared glass samples. The electronegativity and electronic polarizability values revealed the ionic character of glass samples.

Influence of 1.25 MeV gamma rays on optical and luminescent features of Er3+ doped zinc bismuth borate glasses

Abstract Glasses based on 10ZnO-5Na2CO3-10Bi2O3-(75-x)B2O3-xEr2O3 with x = (0, 0.1, 0.3, 0.5, 0.7, 1.0) mol%, were synthesized by melt quenching technique and characterized through optical and luminescent features, before and after irradiating them with high energy (1.25 MeV) gamma rays. The amorphous nature of the glasses and the presence of various structural groups like BiO6, BO3 and BO4 were confirmed through XRD and FTIR measurements. Optical properties were studied through UV–VIS–NIR absorption spectra. Decrease in band gap values after gamma irradiation confirmed the creation of color centers in the glass matrix. Thermally stimulated Luminescence (TL) and Optically Stimulated Luminescence (OSL) spectroscopy techniques were used to study the trap centers induced after irradiation. The number of peaks and their trapping parameters were assessed using the Computerized Glow Curve Deconvolution (CGCD). The linearity in dose response proves their suitability in usage for dosimeter and shields in radiation zones within the dose.

Effects of high dose gamma irradiation on the optical properties of Eu3+ doped zinc sodium bismuth borate glasses for red LEDs

Interaction of 10ZnO-5Na2O-10Bi2O3–74.3B2O3-0.7Eu2O3 glasses exposed to high dose gamma rays were investigated using XRD, FTIR, absorption, photoluminescence followed by thermally and optically stimulated luminescence studies. XRD analysis confirmed the amorphous nature of glasses post-irradiation. Variation in FTIR spectra revealed, structural deformation of borate groups as a result of high dose gamma irradiation. Enhanced glass absorbance and red shift in absorption edge were observed with the increase in gamma dose. Further, radiation-induced absorption coefficient confirmed the trapped charges in the forbidden energy gap supported by Tauc's plot and Urbach energy. Photoluminescence (PL) study demonstrated quenching of luminescence intensity at higher gamma doses. Lifetime of metastable 5D0 state of Eu3+ ions were estimated by the decay curves and color purity was calculated using 1931 CIE chromaticity coordinates (x,y). Thermally and optically stimulated luminescence studies reassured the existence of charges in trap centers due to irradiation. TL glow curve exhibited two broad emission peaks with the corresponding temperature being at 490 K and 625 K. Distinct TL peaks of the material and their kinetic parameters (E, S, τ and b) were determined via Computerized Glow Curve Deconvolution (CGCD) method. Linear behaviour obtained through the dose response of the glass (0.25–3 kGy) proved their suitability for dosimetric application in the food irradiation zones in addition to red LEDs (< 1 kGy).

Improved white light emission in Dy3+ doped LiF–CaO–Bi2O3–B2O3 glasses

The effect of substituting LiF on physical, structural, thermal, optical and photoluminescence properties of Dy3+ doped calcium bismuth borate glasses is reported in the present work. These glasses have been synthesized in the novel compositional range xLiF–(30–x)CaO–20Bi2O3–50B2O3 + 1 mol% of Dy2O3 (x = 0, 2, 5, 7, 10 and 15 mol%, abbreviated as LFx) through convenient melt-quench route. Non-crystalline nature of each composition has been confirmed through X-ray diffraction. Fundamental vibrations of bismuth-borate groups are identified thorough mid-IR absorption spectra. Thermal properties reveal a non-linear trend in glass transition and crystallization temperatures. In order to evaluate optical band gap, analysis of fundamental absorption edge has been done by considering valid Mott's transitions. The compositional trends in optical band gap have supported thermal and infrared absorption results. Evaluation of photoluminescence emission spectra yielded different emission parameters viz. Y/B ratio, color coordinates (x, y) and CCT (correlated color temperature). It has been found that emission of all compositions lie within the white light region and the emission parameters for samples LF2, LF7 and LF10 lie very close to perfect white light (0.333, 0.333). Therefore, these glasses can play the role of useful materials for WLEDs.

Structural and optical properties of rare-earths doped barium bismuth borate glasses

Recently, great importance has been devoted to different glass systems doped with rare-earth ions because of their peculiar properties, in particular in the field of high-energy physics for particle energy measurement. The purpose of the present study was to investigate the optical and physical properties of Dy3+, Er3+, Nd3+ doped glasses belonging to the 20BaO-20Bi2O3-60B2O3 system in which several rare-earths oxide concentrations were added to encounter the requirements for particle energy measurement. High density, low refractive index, high emission intensity (or high scintillation yield) are required for this purpose. Moreover, molar volume, glass transition and melting temperatures, X-ray diffraction and Raman spectra were measured and discussed in order to characterize the glass state. All the properties measured have shown a non-linear trend moving from 1mol% to 10mol% of rare-earths content. At the same time comparison between the trend derived by samples with same stoichiometry but containing different rare earths highlight different behaviors. In particular the highest density has been reached with the glass where Dy2O3 is at 2,5mol%.

Dy3+ doped LiCl–CaO–Bi2O3–B2O3 glasses for WLED applications

Abstract Dy3+ doped calcium bismuth borate glasses were synthesized in the composition range of xLiCl-(30 − x)CaO-20Bi2O3-50B2O3 + 1 mol% Dy2O3 (x = 0, 2, 5, 7, 10 and 15 mol%, LC0, LC2, LC5, LC7, LC10 and LC15 respectively) using conventional melt-quench technique. Broad XRD profiles confirmed non-crystalline nature of synthesized compositions. The compositional dependencies of structural changes (using FTIR spectra), thermal behavior (using DSC thermographs) and optical band gap (using UV–Vis–NIR spectra) were discussed. Photoluminescence (PL) excitation spectra recorded at 577 nm yielded six different excitation peaks belonging to Dy3+ ions. The PL emission spectra recorded at 451 nm were analyzed to extract different light emission parameters viz. Y/B ratio, color coordinates, correlated color temperature (CCT) following CIE 1931 chromaticity diagram. The emission colors were found to lie in white light region and lies very close to standard white light emission. The CCT of sample LC10 (5335 K) is closest to CCT of standard white light (5615 K) which depicted the optimized concentration of LiCl for application of these glasses in WLED application.

Optical absorption and photoluminescence studies of Dy3+ doped alkaline earth bismuth borate glasses

Dy3+ doped alkaline earth bismuth borate glasses were prepared by the conventional melt-quenching method. The prepared glasses were characterized by absorption, excitation, emission and decay curves. Judd–Ofelt parameters were obtained from the absorption spectra recorded at 400–2000nm. All the samples were excited at different wavelengths from UV (350 nm) to blue (450--470 nm) light and respective emission spectra are recorded. The intensity ratio of yellow to blue (Y/B) indicates that Dy3+ ions are present in low symmetry site. B2O3–Bi2O3RO (R = Ba, Sr & Ca) glasses emit efficient white light under different excitation wavelengths, which match well with the emission of commercial GaN-based blue LEDs and InGaN-based LEDs respectively. CIE coordinates were calculated from the emission spectra and found that they fall in white light region. Decay curves show single exponential nature up to 1mol% of Dy3+ concentrations and then turn into non-exponential for 2mol% of Dy3+ ions. Lifetime of these glasses decreases with increase of Dy3+ ion concentration.

The Fluorescence of Pr&amp;lt;sup&amp;gt;3+&amp;lt;/sup&amp;gt; in Zinc Lithium Bismuth Borate Glasses with Large Stimulated Emission Cross Section

Glass sample of Zinc Lithium Bismuth Borate (25-x) Bi2O3:20Li2O:20ZnO:35B2O3:xPr6O11, (where x = 1, 1.5 and 2 mol%) has been prepared by melt-quenching technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The absorption spectra of three Pr3+ doped zinc lithium bismuth borate glasses have been recorded at room temperature. The observed optical spectra are discussed in terms of energy states and the intensity of the transitions. The various interaction parameters like Slater-Condon, Lande, bonding and Racah parameters have been computed. Judd-Ofelt intensity parameters and laser parameters have also been calculated. The stimulated emission cross section (σp) for the transition (3P0 → 3F2) is found to be in the range 3.12 - 10.43 * 10-20 cm2. The σp values are comparatively large suggesting the possible utilization of these materials in laser applications.

Optical and luminescence characteristics of Eu3+ doped zinc bismuth borate (ZBB) glasses for red emitting device

Zinc bismuth borate (ZBB) glasses with chemical composition of (60−x) B2O3: 30Bi2O3: 10ZnO: xEu2O3 for different Eu2O3 concentrations of x=1, 3, 5, 7 and 9mol% were prepared by the conventional melt quenching technique. The density and molar volume of the glasses have been found to increase with Eu2O3 concentration. The IR studies indicated that these glasses were made up of [BiO3], [BO3], [BO4] and [BO] basic structural units. The absorption spectra had revealed two intense bands due to 7F0→7F6 (2076nm) and 7F1→7F6 (2198nm) transitions in the NIR regions. The fractional populations of the (7F0) and (7F1) ground state were 65% and 35%, respectively. Five luminescence bands were observed at 579nm (5D0→7F0), 589nm (5D0→7F1), 613nm (5D0→7F2), 651nm (5D0→7F3) and 696nm (5D0→7F4), when excited by a 465nm source, the most intense red emission was found at 613nm. A shorter decay time of 5D0 excited state was found with increasing of Eu3+ concentration as more asymmetries were created around Eu3+. For comparison, further investigations were carried out with two other glass structures; bismuth borate glass (BB) and zinc borate glass (ZB), doped with Eu3+ in the same range. The ZBB glasses have exhibited with the highest emission intensity especially at 613nm; the intensity for the ZBB was around 7 times of the ZB and twice of the BB glasses.

Optical Basicity and Polarizability of Nd&amp;lt;sup&amp;gt;3+&amp;lt;/sup&amp;gt;-Doped Bismuth Borate Glasses

This paper reports on different physical and optical properties of Nd3+-doped bismuth borate glasses. The glasses containing Nd3+ in (25 - x)Bi2O3:20Li2O:20ZnO:35B2O3:xNd2O3 (where x = 1, 1.5, 2 mol%) have been prepared by melt-quenching method. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. The physical parameters like dielectric constant, refractive index, ionic concentration, oxygen-packing density, inter ionic distance, polaronradius, reflection loss, energy gap, molar refractivity, molar polarizability, electronic polarizability, optical basicity and field strength are computed. On the basis of the measured values of the density and refractive index, the Nd3+ ion concentration in glasses, the polarizability of oxide ions and optical basicity were theoretically determined. The theoretical value of average electronic polarizability and oxide ion polarizability were calculated by using Lorentz-Lorenz formula. Theoretical optical basicity of the glasses is evaluated based on equation proposed by Duffy and Ingram. The metallization criterion has also been calculated on the basis of refractive index and energy gap. The large value of metallization criterion indicates that the glass materials are insulators. The results obtained predict the nature of bonding in the present glasses and provide basis for developing new nonlinear optical material.

Structural and Optical Properties of Ho&lt;sup&gt;3+&lt;/sup&gt; Doped ZnO-Bi&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-B&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Glasses

Ho3+ doped zinc bismuth borate glasses of the composition 10ZnO : 30Bi2O3 : (60-x)B2O3 : xHo2O3 (where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 mol%) were fabricated by conventional melt quenching technique. In order to understand the role of Ho2O3 in these glasses, the density, molar volume and optical spectra were investigated. The molar volume decreases with an increase in Ho2O3 content, which is attributed to the structure becomes more compacted. The absorption spectra of Ho3+ doped in zinc bismuth borate glass correspond to several bands, which are assigned from the ground state, 5I8 to 5G5 (420 nm), 5G6 + 5F1 (451 nm), 5F2 + 5F4 (538 nm), 5F5 (643 nm) and 5I5 (1152 nm). Moreover, the optical basicities were also theoretically determined.

Synthesis and Luminescence Properties of Sm&lt;sup&gt;3+&lt;/sup&gt; in Bismuth Borate Glass

In this research present the results of the analysis of Sm3+ ions doped bismuth borate glasses. Optical measurements such as absorption, excitation and emission profiles have been carried out. Glasses with the chemical compositions (50-x)B2O350Bi2O3xSm2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.50 and 2.5 mol%) were prepared using a conventional melt-quenching method. The emission spectrum of Sm3+ doped bismuth borate glasses has shown the emission transitions of to 4G5/26H 5/2 (563 nm), 4G5/26H 7/2 (598 nm), 4G5/26H9/2 (644 nm). Energy level schemes relating to the emission mechanisms involved in Sm3+ glasses have been given.

Reddish-orange emission from Pr3+ doped zinc alumino bismuth borate glasses

Praseodymium doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by melt quenching technique and characterized by optical absorption and emission studies. The glassy nature of these glasses has been confirmed through XRD spectral measurements. From the absorption spectra, the Judd–Ofelt intensity parameters Ωλ (λ=2, 4 and 6) and other radiative properties like transition probability (AR), radiative lifetimes (τR) and branching ratios (βR) have been evaluated. Emission spectra were measured for different concentrations of Pr3+ ions doped glasses by exciting the glasses at 445nm. The intensity of Pr3+ emission spectra increases from 0.1 to 1mol% and beyond 1mol% concentration quenching is observed. The suitable concentration of Pr3+ ions in ZnAlBiB glasses to act as a good lasing material at reddish-orange wavelength (604nm) region has been discussed by measuring the emission cross-sections for the intense emission transition 1D2→3H4. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for reddish-orange emission. From the measured emission cross-sections and CIE chromaticity co-ordinates, it was found that 1mol% of Pr3+ is aptly suitable for the development of visible reddish-orange lasers.

Spectroscopic properties and luminescence behavior of Nd3+ doped zinc alumino bismuth borate glasses

Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of neodymium are prepared by using the melt quenching technique to study their physical, absorption and luminescence properties to understand the lasing potentialities of these glasses. From the absorption spectra various spectroscopic parameters and Judd–Ofelt (JO) parameters are evaluated. These JO parameters are used to calculate the transition probability (A), radiative lifetime (τR), and branching ratios (βR) for most of the fluorescent levels of Nd3+. The emission spectra recorded for these glasses gives three prominent transitions 4F3/2→4I9/2, 4F3/2→4I11/2 and 4F3/2→4I13/2 for which effective band widths (ΔλP) and stimulated emission cross-sections (σse) are evaluated. Branching ratios and stimulated emission cross-sections measured for all these glasses show that the 4F3/2→4I11/2 transition under investigation has the potential for laser applications. The intensity of Nd3+ emission spectra increases with increasing concentrations of Nd3+ up to 1mol% and beyond 1mol% the concentration quenching is observed. The high stimulated emission cross-section and branching ratios from the present glasses suggests their potential for infrared lasers. From the absorption and emission spectral studies it was found that, 1mol% of Nd3+ ion concentration is optimum for Zinc Alumino Bismuth Borate glasses to generate a strong laser emission at 1060nm.

Visible fluorescence characteristics of Dy3+ doped zinc alumino bismuth borate glasses for optoelectronic devices

Abstract Zinc Alumino Bismuth borate (ZnAlBiB) optical glasses of different compositions doped with 1 mol% of Dy 3+ ions were prepared by the conventional melt quenching technique and investigated by the XRD, optical absorption, photoluminescence and decay curve analysis. The glassy nature of ZnAlBiB host has been confirmed through XRD measurements. From the absorption spectral measurements, the three phenomenological intensity parameters Ω λ ( λ =2,4 and 6) have been determined from the Judd–Ofelt (J–O) theory. By using JO intensity parameters, several radiative properties such as transition probability ( A R ), branching ratio ( β R ) and radiative lifetimes ( τ R ) have been determined. The room temperature photoluminescence spectra of Dy 3+ ions doped ZnAlBiB glasses gave two relatively intense emission bands 4 F 9/2 → 6 H 15/2 (blue), 4 F 9/2 → 6 H 13/2 (yellow) along with one faint band. The higher values of branching ratios and stimulated emission cross-sections for the 4 F 9/2 → 6 H 13/2 transition suggest the utility of these glasses as potential laser materials. The decay curves have been recorded for all the ZnAlBiB glasses to measure the quantum efficiency of these glasses by measuring the experimental lifetime ( τ exp ). The radiative properties and CIE chromaticity co-ordinates have been evaluated from the emission spectra to understand the feasibility of these glasses for optoelectronic devices.

X-RAYS LUMINESCENCE, OPTICAL AND PHYSICAL STUDIES OF BI2O3-B&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-SM&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; GLASSES SYSTEM

Sm3+-doped bismuth borate glasses of the composition (50-x) SiO2: 50B2O3: xSm2O3 (where x = 0.00, 0.50, 1.00, 1.50, 2.00 and 2.50 mol%) have been synthesized by conventional melt quenching technique. In order to understand the role of Sm2O3 in bismuth borate glasses, the density, molar volume, refractive index and optical absorption were investigated. The results show that density, molar volume and refractive index of glasses increased with increasing Sm2O3 concentration. The increase of molar volume with Sm2O3 concentration is due to the increase of Non-Bridging Oxygen (NBOs) in the glass matrix. The optical absorption spectra were measured in the wavelength range from 300-1100 nm and the optical band gaps were determined. It was found that the optical band gap decreased with the increase of Sm2O3 concentration. Moreover, the x-rays luminescence of Sm2O3 glasses samples were measured and shows emission band at 4G5/2?6H5/2 (569 nm), 4G5/2?6H7/2 (598 nm), 4G5/2?6H9/2 (641 nm) and 4G5/2?6H11/2 (705 nm). This investigation have been used as the basis for developing optical amplifier or glass scintillator.