Doped Borate Glasses Research Articles

The Gd2O3 effect study on properties of CaGdSiB:Tb3+ glass for photonics applications

Tb3+ doped calcium gadolinium silica borate glasses (CaGdSiB:Tb3+) were prepared to study the influence of Gd2O3 concentration on physical, glass network, optical and luminescence properties. Glass density and molar volume increased with increment of Gd2O3 concentration. The enlargement of molar volume and evolution of FTIR spectra confirmed the non-bridging oxygen more occurring in glass network with increment of Gd2O3. Tb3+ in glass absorbed photons in visible light and near-infrared region. Glass exhibited the strongest luminescence intensity of Tb3+ at 542 nm under 275 nm excitation, passing through the Gd3+ - Tb3+ energy transfer. The overall color of emission is green in CIE 1931 chromaticity. The emission intensity did not show clear relation with Gd2O3 concentration. However, glass with 22.5 mol% of Gd2O3 possessed the highest emission intensity. The luminescence decay times of Tb3+ was about 2 ms which decreased via increasing of Gd2O3 content. CaGdSiB:Tb3+ glass performs the potential for using as a scintillator for detector with integration mode and a green light source medium.

Nonlinear optical studies of sodium borate glasses embedded with gold nanoparticles

Optical glasses possessing large third-order optical nonlinear susceptibility and fast response times are promising materials for the development of advanced nonlinear photonic devices. In this context, gold nanoparticle (NP)-doped borate glasses were synthesized via the melt-quench method. The nonlinear optical (NLO) properties of thus prepared glasses were investigated at different wavelengths (i.e., at 532 nm using nanosecond pulses, at 750 nm, 800 nm, and 850 nm wavelengths using femtosecond, MHz pulses). At 532 nm, open aperture (OA) Z-scan signatures of gold NP-doped borate glasses demonstrated reverse saturable absorption (RSA), attributed to mixed intra-band and interband transitions, while in the 750‒850 nm region, the OA Z-scan data revealed the presence of saturable absorption (SA), possibly due to intra-band transitions. The NLO coefficients were evaluated at all the spectral regions and further compared with some of the recently reported glasses. The magnitudes of obtained NLO coefficients clearly demonstrate that the investigated glasses are potential materials for photonic device applications.

Broadband emission and flat optical gain glass containing Ag aggregates for tunable laser

AbstractSpectroscopic properties of Sm3+‐doped borate glass with silver aggregates were investigated, and it was found that the glass presented broad excitation and emission band covering violet‐infrared region. Furthermore, the optical gain coefficients at various wavelengths were measured via an amplified spontaneous emission technique, it was confirmed that the glass displayed flat net optical gain coefficient in almost full visible region. In addition, the fluorescent temperature quenching of the glass was examined, and it was seen that about 50% of room temperature emission intensity was kept when the sample was heated up to 325°C.

Fabrication and Characterization of Sm3+ Doped Zinc Barium Borate Glasses

Zinc-barium-borate glasses with the composition (60 − x)B2O3–10ZnO–30BaO–xSm2O3 (where x = 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) doped with Sm3+ ions have been prepared, and their physical and optical properties are investigated. The photoluminescence spectra recorded under the 403-nm excitation exhibited the emission bands at 564, 600, 647, and 710 nm corresponding to the transition 4 G5/2 →6 Hj (j = 5/2, 7/2, 9/2, 11/2), respectively. Judd–Ofelt intensity parameters (Ωl, l = 2, 4 and 6) have been evaluated, and the radiative transition probabilities, emission cross-section, and branching ratios for the excited levels of Sm3+ ionsare predicted. The lifetime of the 4 G5/2 level is found to decrease with an increase in the Sm3+ ion concentration.

Tb3+, Eu3+, and Dy3+ doped lithium borate and lithium aluminoborate glass: Glass properties and photoluminescence quantum efficiency

The glass properties as well as the photoluminescence quantum efficiency of Li2O-B2O3 and Li2O-Al2O3-B2O3 glasses are investigated; both glass systems are optically-activated by the addition of the lanthanide ions Tb3+, Eu3+, and Dy3+. Glass transition, glass crystallization, and glass melting temperatures as well as glass forming temperature ranges are determined upon varying the modifier-to-former (Li2O-to-B2O3) ratio in the range between 1:6 to 1:2. For lithium borate glass, the risk of spontaneous crystallization decreases upon decreasing the lithium concentration. The photoluminescence quantum efficiency increases slightly upon decreasing the lithium concentration with the value of a Al2O3-containing sample always lower than that of the Al2O3-free correspondent.

Blue-yellow emission adjustability with aluminium incorporation for cool to warm white light generation in dysprosium doped borate glasses

A series of white light emitting Dy3+ doped lead borate (DY) and lead alumino borate (DYA) glasses have been prepared by melt quench technique and are explored by XRD, FTIR, optical absorptions, fluorescence and density measurements. In this paper an effort has been made to compare the structural changes and luminescence efficiencies of prepared glasses by changing dysprosium oxide content and glass network environment by adding aluminium oxide. The XRD profile of all the glasses confirms their amorphous nature and FTIR study shows the presence of BO3 and BO4 groups. Incorporation of Al2O3 in the glass system is responsible for a strong effect on luminescence of the present glass system. There is a strong correlation between Dy3+ ions concentration and the host glass composition on the energy transfer mechanism. The decay curves deviate gradually from single exponential function at lower concentrations to non-exponential behavior at higher concentrations. The Inokutie Hirayama (IH) model for S= 6 fits well the non-exponential decay curves that indicate dipole-dipole type energy transfer between donor and acceptor ions. The calculated chromaticity coordinates lie in the white region of CIE 1931 chromaticity diagram and are in excellent proximity with the standard equal energy white illuminant (0.333, 0.333). Furthermore, the calculated correlated color temperature and the yellow to blue (Y/B) ratio of the synthesized photonic glasses may offer the possibility of tuning the white light by varying concentration and host environment which could be useful for various photonic based device applications.

Spectroscopic studies of Dy3+ doped borate glasses for cool white light generation

The Dy3+ ions doped Na2O-ZnO-Al2O3-B2O3 (BAZN) glasses with variable doping concentrations were synthesized by melt-quenching technique. The XRD pattern reveals amorphous nature of the as-synthesized glass. The FT-IR spectrum reveals various stretching and bending vibration of aluminates, borate and some other groups. The emission spectra exhibit two intense bands at around 482 nm (blue) and 575 nm (yellow) corresponding to the 4F9/2 → 6H15/2 and F9/2 → 6H13/2 transitions respectively. The CIE chromaticity coordinates of the as-synthesized glasses are lying in white region and in proximity to the coordinates for white light specified by National Television Standard Committee and commercial phosphor converted white light emitting devices. The decay profile of BAZN glasses showed bi-exponential behavior due to the energy transfer mechanism from excited donor ion to unexcited acceptor ion. The above-mentioned studies show potential of the as-synthesized Dy3+ doped BAZN glasses in solid state lighting applications.

Preparation and optical properties of borate glass doped with MnO2

In this contribution, MnO2 doped borate glass matrix with ratios 0.0, 0.5, 1.0, 1.5 and 2.0 wt% were prepared utilizing melting method. The structural characterization of these glass samples was performed via X- ray diffraction measurements. Optical absorption analyses within the 200–1000 nm wavelength range were performed to characterize the samples. The direct and indirect optical energy gaps (Eopt) decreased however Urbach energy (EU) increased with increasing MnO2 concentration. The refractive index, and optical conductivity values are observed to increase with increasing MnO2 concentration. FTIR spectra of borate glass doped with 0.0, 0.5, 1.0, 1.5 and 2.0 wt% MnO2 revealed the presence of absorption bands due to Mn2+.

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 Luminescent property of Holmium doped Borate Glasses

Holmium doped Lithium Lead Borate glasses of different compositions were prepared by melt quenching technique. Fourier transform infrared investigations on lithium lead borate glasses have been made to study the local order and vibrations of atoms in the glass network and it contains mainly BO3 and BO4 structural units. Photoluminescence techniques were employed to investigate the luminescent property of these glasses excited at 451nm. Blue emission have been observed from the transition 495 (5F3 → 5I8).

Emission cross section and optical gain of 1.06mm laser Nd3+ doped borate glasses

In this paper we develop the optical pumping system based on 805 nm laser diode as photo-pumped source. Laser with a wavelength of 1064 nm is used as reference source and passed in a laser glass medium. Laser glass medium was synthesized from chemical compositions of (65-x)B2O3-15Na2O-10PbO-5ZnO-5Li2O-xNd2O3 (with x = 0.05, 0.1, 0.5, 1.0, 2.0 and 4.0). The emission spectra confirms that there are three emission peaks located at 946 nm, 1064 nm and 1350 nm corresponding to 4F3/2®4I9/2, 4F3/2®4I11/2 and 4F3/2®4I13/2 respectively. The emission cross section relatively higher for the 4F3/2®4I11/2 transition shows the compatibility of these glasses for near infra-red laser application. The measurements of optical gain had been carried out by using lock-in amplifier with voltage as output signal. From output voltage converted to optical gain in dB. The glass medium with 1.0 Nd3+ label was obtained the maximum optical gain with incident power 900 mW.

Luminescence study and Judd-Ofelt analysis of Nd3+ doped lithium lanthanum borate glass for green laser device

Lithium lanthanum borated glasses doped with Nd3+ (LiLaBNd) were synthesized to study in luminescence properties and laser potential. Refractive index, density and molar volume of glass increase with increasing of Nd3+ concentration. Glasses absorb photon in visible light and near- infrared region corresponding to energy transition from 4I9/2 ground state of Nd3+. Covalent nature and interaction between Nd3+ and ligand result to small red shift of Nd3+ energy level. The strongest emission with 1059 nm corresponds to 4F3/2→4I11/2 transition of Nd3+ under 808 nm excitation. The optimum concentration of Nd2O3 for this glass is 0.50 mol% which creates the maximum intensity of emission. Luminescence decay curve indicated cross relaxation process between Nd3+with low probability and life time value as 114 microsecond for 0.50 mol% doped glass. Judd-Ofelt analysis was used to evaluate several radiative parameters. Narrow effective bandwidth, high stimulated emission cross section and branching ratio indicated the advantage potential to develop LiLaBNd glass for using as laser medium in green emitting laser device.

Spectroscopy properties of Er3+ ion doped ZnO-Al2O3-BaO-B2O3 glass for photonic application

The physical, optical and luminescence properties of Er3+ ion doped borate glass have been developed by melt-quenching technique. The density and molar volume of glass medium increased with increasing Er2O3 concentration due to the enhancement of non-bridging oxygen intensity in the glass structure. The quenching concentration effect was obtained at 2.0 mol% Er2O3. The strongest absorption occurred at 524 nm (4I15→2H1). The emission spectra excited by λex = 524 nm showed the 4I13/2→4I15/2 transition centered at 1534 nm. From presented data, the borate glass doped Er3+ ion is a potential material to be developed for telecommunication and an optical amplifier.

Linear and nonlinear optical properties of gold nanoparticles doped borate glasses

Gold nanoparticles (NPs) embedded in sodium antimony borate glass system were fabricated and their optical, physical, structural, ultrafast nonlinear optical properties were studied and analyzed. Metallic gold NPs were synthesized using thermal reducing agent Sb2O3 and demonstrated the reduction mechanism of Au3+/Au+→Au0 by using reduction potentials of corresponding redox system. UV–Visible spectroscopy measurements have revealed the characteristic surface plasmon resonance (SPR) of Au NPs at ~565nm, attributed due to interband transition. The micrographs of High-Resolution Transmission Electron Microscopy (HR-TEM) confirmed the existence of uniformly distributed spherical shaped Au NPs with particle sizes in the 8–45nm range with an average particle size of 25nm. The ultrafast nonlinear optical properties of gold doped glasses were investigated using the Z-scan technique at a non-resonant wavelength (λ=800nm, 80MHz repetition rate) with femtosecond (fs) Ti:sapphire laser pulses. Z-scan measurements of undoped glass depicted are verse saturable absorption (RSA) type of nonlinearity whereas the gold-doped glass demonstrated saturable absorption (SA) kind of nonlinearity due to intraband (sp→sp) transitions. The Z-scan data demonstrated that the investigated glasses are potential materials for the applications in nonlinear optics devices, particularly in optical switching devices.

Photoluminescence investigations on Sm3+ ions doped borate glasses for tricolor w-LEDs and lasers

This work describes mainly the optical absorption, photoluminescence (PL) and decay spectral properties of Sm3+ ions doped borate glasses to understand their possible usage in tricolor w-LEDs and lasers.The XRD spectrum recorded for an un-doped glass confirms glassy nature of the as prepared glass. The Judd-Ofelt (J-O) intensity parameters evaluated from experimental oscillator strengths were used in estimating the various radiative parameters. Under 402 nm excitation, the PL spectra exhibit intense emission at 600 nm for which the decay spectral profiles were recorded.The decay profiles are converting from single exponential to non-exponential with increase in Sm3+ ion concentration ensuing decrease in experimental lifetimes which may be attributed to the efficient energy transfer through cross-relaxation process. The non-exponential decay curves fitted to I-H model reveals the interaction between the Sm3+ ions as dipole-dipole in nature. From the evaluated emission cross-sections, quantum efficiency, branching ratios and CIE co-ordinates, it is concluded that 1 mol% Sm3+ ions in these glasses are aptly suitable to fabricate reddish-orange luminescent devices.

Optical and Electrical Properties of Nd3+ Doped TeBiY Borate Glasses

60B2O3-30Bi2O3-5TeO2-(5–x)Y2O3-xNd2O3 mole% (0 ≤ × ≤ 4) glasses were prepared by the usual experimental glass-melting procedures. This work was carried out to study the effect of Nd2 O 3 on the properties of the glasses studied and thereby their structure. The effect of the replacement of Y2O3 by Nd2O3 on the optical and electrical properties of the glass samples was studied. The results obtained showed that the values of density, oxygen packing density, concentration of Nd ions and field strength were found to increase with increase of the Nd2O3. On the other hand the molar volume, inter-nuclear distance and polaron radius showed the opposite behavior with increasing Nd2O3 content. The results also showed that the direct and indirect optical band gap were found to increase which indicate that increasing the concentration of Nd2O3 leads to a change in the structure of glasses induced by Nd2O3. Dc and ac conductivities values were found to increase, whereas the dc activation energy decreases, with increasing Nd2O3 concentration. An increase in the dielectric constant values with increasing Nd2O3 content is observed. The results suggest that the CBH model seems to be the appropriate model for the ac conductivity in the studied glasses.

Anomalous DC electrical conductivity in mixed transition metal ions doped borate glasses

A novel series of borate glasses in the composition, xCo3O4+(50−x) (V2O5)+50 B2O3 where x=0.05 to 0.45 have been prepared by melt quenching technique. X-ray diffraction studies confirmed the non-crystalline nature of the samples. The room temperature density and molar volume varied non-linearly with cobalt concentration. Electrical conductivity and activation energy were determined and both varied non-linearly with cobalt concentration. Conductivity reached minimum and activation energy reached maximum at x=0.4 of cobalt concentration. This anomalous behavior is due to the enhancement of Anderson localization caused by increase in configurational disorder. Various polaron related parameters were investigated in the light of Mott's SPH model for T>θD2. The density of states at fermi level was determined using Greaves VRH model which adequately explains conductivity for T<θD2. The nonlinear variation in various physical parameters with second TMI is attributed to the mixed transition effect.

The effect of Alkali Type on the Optical Behavior of Cu Doped Borate Glass Bandpass Filter

The effect of Alkali Type on the Optical Behavior of Cu Doped Borate Glass Bandpass Filter

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%.

Structural, thermal, optical and dielectric studies of Dy3+: B2O3-ZnO-PbO-Na2O-CaO glasses for white LEDs application

Dy3+-doped borate glasses with nominal composition (60-x) B2O3-10 ZnO-10 PbO-10 Na2O-10 CaO-(x) Dy2O3 (x = 0, 0.1, 0.2, 0.5, 0.75, 1.0, 1.5 and 2.0 mol%) were prepared by the melt quenching technique. The XRD and SEM confirm the amorphous nature of the glasses and through EDAX, all the related elements were found in the synthesized glasses. The vibrations of metal cations such as Pb2+ and Zn2+, B–O–B bond bending vibrations from pentaborate groups, bending vibrations of BO3 triangles, and stretching vibrations of tetrahedral BO4− units etc. are identified from the respective FTIR and Raman spectra including the non-hygroscopic nature of the synthesized glasses. The TGA and DSC measurements were performed to study thermal properties, where ΔT >100 °C (ΔT = Tx – Tg) for all the glasses. Among all the Dy3+-doped glasses, the 0.75 mol% Dy3+-doped glass shows the highest PL intensity with four emissions, where the two transitions corresponding to 4F9/2 → 6H15/2 (blue) and 4F9/2 → 6H13/2 (yellow) are observed more intense than the others. The CIE chromaticity (x,y) coordinates for BZPNCDy 0.1 mol% glass are (0.398, 0.430), close to the white light region in the CIE 1931 chromaticity diagram. The dielectric properties of the 0.75 mol% Dy3+-doped glass such as dielectric constant, dielectric loss and AC conductivity were studied in the various frequencies and temperature.