Characterization of new Sb2O3-based multicomponent heavy metal oxide glasses

International audienceNew Sb2O3-based multicomponent heavy metal oxide glasses in the Sb2O3-Na2O-WO3-PbO system were prepared using a conventional melt-quenching technique. Glass formation behavior of these glasses and their thermal, physical and structural properties were investigated using X-ray diffraction (XRD), scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS), differential scanning calorimetry (DSC), UV-Vis-NIR spectroscopy and Fourier transform infrared (FTIR) spectroscopy analyses according to the increasing PbO concentration by keeping the Sb2O3/WO3 ratio constant. Thermal analysis of the glasses were realized in terms of glass transition temperature (Tg), crystallization temperature (Tc/Tp), glass stability against crystallization (∆T), activation energy of the glass transition reaction (Eg) and fragility parameter (m). Density (ρ), molar volume (VM), oxygen molar volume (VO), oxygen packing density (OPD), refractive index, band gap energy (Eg), average cross-link density (c n), number of bonds per unit volume (nb) and Poisson's ratio (μcal) values were calculated for the interpretation of physical and structural properties of the glasses. FTIR spectra of the glasses were evaluated in terms of structural transformations on the glass network

Structural and Optical Investigation of Transition Metal Oxide-Doped PbCl2-TeO2 Glasses

Bu çalışmada, iyi doğrusal olmayan optik özellikleri ve yüksek yarı iletkenlik potansiyelleri nedeniyle opto-elektronik uygulamalarda kullanım için elverişli sistemler olan geçiş metal oksit (GMO) katkılı tellürit camlar yapısal ve optik açıdan incelenmiştir. Yapılan deneysel çalışmalarda, PbCl2 -TeO2 cam sistemine katkılandırılan Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO geçiş metal oksitlerinin camların fiziksel ve yapısal özelliklerine etkisi araştırılmış ve değişen GMO türü ile camların kızılötesi bölge optik geçirgenlik özelliklerinde meydana gelen değişimler incelenmiştir. Bu amaçla, (2x)GMO–(25-x)PbCl2–(75-x)TeO2 , x = 0 ve 10 mol% (GMO: Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO) sistemine ait camların yoğunluk, molar hacim, oksijen molar hacim, oksijen paketlenme yoğunluğu, ortalama çapraz bağlanma yoğunluğu gibi fiziksel parametreleri belirlenerek camların yapısal özellikleri ile ilişkilendirilmiştir. Geçiş metal oksit katkısının PbCl2 -TeO2 camların birim hacimdeki bağ sayısını arttırarak boşluk hacmini azalttığı ve yapıyı daha sıkı paketlenebilir hale getirdiği belirlenmiştir. Ayrıca FTIR analizleri ile camların kızılötesi bölgedeki geçirgenlik özellikleri incelenmiş ve GMO-PbCl2 -TeO2 camların yüksek kızılötesi bölge geçirgenlik ve yüksek kızılötesi bölge geçirgenlik aralığı değerleri gösterdiği tespit edilmiştir.In the present study, structural and optical investigations of transition metal oxide (TMO)-doped tellurite glasses, which are promising glass matrices for opto-electronic applications due to their good non-linear optical properties and high semiconducting behavior, were realized. In the experimental studies, the effect of different transition metal oxides (Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO) on physical and structural properties of PbCl2-TeO2 glasses were determined and the changes in the infrared transmittance behavior of these glasses were investigated for different TMO-doped samples. For this purpose, physical investigation of glasses in the (2x)GMO–(25-x)PbCl2–(75-x)TeO2 , x = 0 and 10 mol% (GMO: Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO) system was realized by determining the density, molar volume, oxygen molar volume, oxygen packing density, average cross-link density and number of bonds per unit volume values. It was found that the addition of transition metal oxides provide a more tightly packed network by decreasing the excess free volume with increasing the number of bonds per unit volume. Accordingly, the structural changes in the glass network were determined and the infrared transmittance properties of the glasses were evaluated running FTIR analysis. It was also detected that GMO-PbCl2 -TeO2 glasses show high infrared transmission in a wide infrared range

Structural and Optical Investigation of Transition Metal Oxide-Doped PbCl2-TeO2 Glasses

Bu çalışmada, iyi doğrusal olmayan optik özellikleri ve yüksek yarı iletkenlik potansiyelleri nedeniyle opto-elektronik uygulamalarda kullanım için elverişli sistemler olan geçiş metal oksit (GMO) katkılı tellürit camlar yapısal ve optik açıdan incelenmiştir. Yapılan deneysel çalışmalarda, PbCl2 -TeO2 cam sistemine katkılandırılan Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO geçiş metal oksitlerinin camların fiziksel ve yapısal özelliklerine etkisi araştırılmış ve değişen GMO türü ile camların kızılötesi bölge optik geçirgenlik özelliklerinde meydana gelen değişimler incelenmiştir. Bu amaçla, (2x)GMO–(25-x)PbCl2–(75-x)TeO2 , x = 0 ve 10 mol% (GMO: Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO) sistemine ait camların yoğunluk, molar hacim, oksijen molar hacim, oksijen paketlenme yoğunluğu, ortalama çapraz bağlanma yoğunluğu gibi fiziksel parametreleri belirlenerek camların yapısal özellikleri ile ilişkilendirilmiştir. Geçiş metal oksit katkısının PbCl2 -TeO2 camların birim hacimdeki bağ sayısını arttırarak boşluk hacmini azalttığı ve yapıyı daha sıkı paketlenebilir hale getirdiği belirlenmiştir. Ayrıca FTIR analizleri ile camların kızılötesi bölgedeki geçirgenlik özellikleri incelenmiş ve GMO-PbCl2 -TeO2 camların yüksek kızılötesi bölge geçirgenlik ve yüksek kızılötesi bölge geçirgenlik aralığı değerleri gösterdiği tespit edilmiştir.In the present study, structural and optical investigations of transition metal oxide (TMO)-doped tellurite glasses, which are promising glass matrices for opto-electronic applications due to their good non-linear optical properties and high semiconducting behavior, were realized. In the experimental studies, the effect of different transition metal oxides (Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO) on physical and structural properties of PbCl2-TeO2 glasses were determined and the changes in the infrared transmittance behavior of these glasses were investigated for different TMO-doped samples. For this purpose, physical investigation of glasses in the (2x)GMO–(25-x)PbCl2–(75-x)TeO2 , x = 0 and 10 mol% (GMO: Sb2O3 , WO3 , MoO3 , Bi2O3 , ZnO) system was realized by determining the density, molar volume, oxygen molar volume, oxygen packing density, average cross-link density and number of bonds per unit volume values. It was found that the addition of transition metal oxides provide a more tightly packed network by decreasing the excess free volume with increasing the number of bonds per unit volume. Accordingly, the structural changes in the glass network were determined and the infrared transmittance properties of the glasses were evaluated running FTIR analysis. It was also detected that GMO-PbCl2 -TeO2 glasses show high infrared transmission in a wide infrared range

The coupling of blue emitting carbon dots with Eu3+/Tb3+ co-doped luminescent glasses for utilization in white light emitting diodes

Lanthanide-doped luminescent glasses have attracted tremendous attention in modern optoelectronic applications, especially for solid-state white light-emitting diodes (WLEDs). Eu3+/Tb3+ co-doped luminescent glasses are well-known to emit intense yellowish-orange light resulting from the energy transfer from green-emitting sensitizer Tb3+ ions to red-emitting activator Eu3+ ions. Obtaining highly efficient blue light from lanthanide ions remains a challenge due to their weak down-converted emission. In this work, we attempt to use the unique characteristics of blue-emitting carbon dots (BCDs), i.e., a broad emission spectrum, ease of synthesis, and high stability, to compensate for this blue light deficiency problem. Correspondingly, a new strategy is proposed by coupling BCDs with Eu3+/Tb3+ co-doped glasses for their potential utilization in WLEDs. Hence, Eu3+/Tb3+ co-doped glasses are prepared in different thicknesses, i.e., 0.8, 1, and 1.5 mm, via the conventional melt-quenching method and subsequently spin-coated with BCDs to achieve adjustable photoluminescence quantum yield (PLQY) values. Ultimately, a proof-of-concept WLED is prepared using a 0.8 mm thick BCD-coated Eu3+/Tb3+ co-doped luminescent glass exhibiting outstanding luminescence performance with a CRI value of 92, a CCT of 4683 K, color coordinates of (x = 0.3299, y = 0.3421), a satisfying PLQY value of 55.58%, and a corresponding LER value of 316 lm W−1 under the excitation of a 375 nm UV LED. BCD-coated Eu3+/Tb3+ co-doped luminescent glasses show excellent stability against photobleaching, temperature variations, and humidity. The findings of this work indicate that the coupling of BCDs with Eu3+/Tb3+ co-doped luminescent glasses holds great potential as a substitute for traditional solid-state lighting sources

Bright white light emission from blue emitting carbon dot-coated Dy3+-doped luminescent glasses

Dy3+-doped luminescent glasses have received great attention due to their ability to emit white light at a suitable yellow-to-blue intensity ratio. However, achieving bright white light using single Dy3+-doped glasses remains a challenge due to the hypersensitivity of the emission band at 575 nm — usually resulting in intense yellow emission. In this work, we present a novel approach for compensating for the blue emission deficiency of Dy3+ to produce resin-free white light-emitting diodes (WLEDs) by synthesizing two series of Dy3+-doped glasses from tellurite and silicate systems on which blue-emitting carbon dots (BCDs) are spin-coated. The structural, chemical, optical, and luminescence properties of tellurite and silicate glasses are compared and discussed in detail. White light emissions are obtained upon 365-nm excitation for BCD-coated Dy3+-doped tellurite and silicate glasses with color coordinates of (x = 0.31, y = 0.33) and (x = 0.31, y = 0.34) and correlated color temperatures (CCT) of 5518 K and 5316 K, respectively. BCDs coating increases photoluminescence quantum yield (PLQY) values from 3.10 % to 5.62 % and from 20.81 % to 31.49 % for tellurite and silicate glasses, respectively. Ultimately, the findings in this work show the potential of BCD-coated luminescent glasses with excellent luminescent properties to be considered in solid-state lighting applications

Novel HMO-Glasses with Sb2O3 and TeO2 for Nuclear Radiation Shielding Purposes: A Comparative Analysis with Traditional and Novel Shields

The radiation shielding characteristics of samples from two TeO2 and Sb2O3-based basic glass groups were investigated in this research. TeO2 and Sb2O3-based glasses were determined in the research as six samples with a composition of 10WO3-(x)MoO3-(90 − x)(TeO2/Sb2O3) (x = 10, 20, 30). A general purpose MCNPX Monte Carlo code and Phy-X/PSD platform were used to estimate the radiation shielding characteristics. Accordingly, the linear and mass attenuation coefficients, half value layer, mean free path, variation of the effective atomic number with photon energy, exposure and built-up energy factors, and effective removal cross-section values were determined. It was determined that the results that were produced using the two different techniques were consistent. Based on the collected data, the most remarkable findings were found to be associated with the sample classified as T80 (10WO3 + 10MoO3 + 80TeO2). The current study showed that material density was as equally important as composition in modifying radiation shielding characteristics. With the T80 sample with the greatest density (5.61 g/cm3) achieving the best results. Additionally, the acquired findings were compared to the radiation shielding characteristics of various glass and concrete materials. Increasing the quantity of MoO3 additive, a known heavy metal oxide, in these TeO2 and Sb2O3-based glasses may have a detrimental impact on the change in radiation shielding characteristics