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Preliminary Characterization of Glass/Alumina Composite Using Laser Powder Bed Fusion (L-PBF) Additive Manufacturing
摘要： Powder bed fusion (PBF) additive manufacturing (AM) is currently used to produce high-efficiency, high-density, and high-performance products for a variety of applications. However, existing AM methods are applicable only to metal materials and not to high-melting-point ceramics. Here, we develop a composite material for PBF AM by adding Al2O3 to a glass material using laser melting. Al2O3 and a black pigment are added to a synthesized glass frit for improving the composite strength and increased laser-light absorption, respectively. Our sample analysis shows that the glass melts to form a composite when the mixture is laser-irradiated. To improve the sintering density, we heat-treat the sample at 750°C to synthesize a high-density glass frit composite. As per our X-ray diffraction (XRD) analysis to confirm the reactivity of the glass frit and Al2O3, we find that no reactions occur between glass and crystalline Al2O3. Moreover, we obtain a high sample density of ≥95% of the theoretical density. We also evaluate the composite’s mechanical properties as a function of the Al2O3 content. Our approach facilitates the manufacturing of ceramic 3D structures using glass materials through PBF AM and affords the benefits of reduced process cost, improved performance, newer functionalities, and increased value addition.
关键词： density,powder bed fusion,additive manufacturing,mechanical property,3D printing,glass/alumina composite
更新于2025-09-23 15:21:01
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Tunable Chromaticity and High Color Rendering Index of WLEDs with CaAlSiN <sub/>3</sub> :Eu <sup>2+</sup> and YAG:Ce <sup>3+</sup> Dual Phosphora??ina??silicaa??glass
摘要： Phosphors-in-glass (PiG), which serves as a potential bi-replacement of both phosphors and organic encapsulants in high-power white light-emitting diodes (WLEDs), has captured much attention due to its high thermal stability and excellent luminescent properties. However, due to the high temperature-sensitivity and the chemical reactions between phosphors with glass matrix, a variety of phosphors, especially red phosphors could be hardly dispersed into the glass without thermal quenching and decomposition, which greatly limits the improvement of color rendering index and chromaticity tunability of the WLEDs. In this study, adopting the mesoporous silica (FDU-12) and commercial phosphors as raw materials, the phosphors-in-silica-glasses (PiSGs) embedded with red phosphor CaAlSiN3:Eu2+ and yellow phosphor YAG:Ce3+ have been successfully prepared at low sintering temperature (950 ?C) and short preparation time (10 min) using spark plasma sintering. Owing to the well preservation of the originally emissive properties of the embedded phosphors, the warm WLEDs with tunable chromaticity and exhibited a superior performance with LE of 133 lm/W, CCT of 3970 K and CRI of 81 were fabricated by encapsulating the as-prepared PiSGs on the blue chips. Moreover, the PiSG composite exhibits a high thermal conductivity up to 1.6 W/m·K.
关键词： white light-emitting diodes,phosphor in silica glass,tunable chromaticity,mesoporous silica
更新于2025-09-23 15:21:01
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Laser Sources Based on Rare-Earth Ion Doped Tellurite Glass Fibers and Microspheres
摘要： In recent years, huge progress has been made in the development of rare-earth ion doped tellurite glass laser sources, ranging from watt- and multiwatt-level fiber lasers to nanowatt level microsphere lasers. Significant success has been achieved in extending the spectral range of tellurite fiber lasers generating at wavelengths beyond 2 μm as well as in theoretical understanding. This review is aimed at discussing the state of the art of neodymium-, erbium-, thulium-, and holmium-doped tellurite glass fiber and microsphere lasers.
关键词： microsphere laser,tellurite glass fiber,microlaser,rare-earth ions,tellurite fiber laser
更新于2025-09-23 15:21:01
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Tl2S-GeS GeS2 system: Glass formation, macroscopic properties, and charge transport
摘要： the previously obtained conductivity and A relevant approach was found to study the glass-forming region, macroscopic properties and electrical conductivity changes in the Tl2S-GeS-GeS2 system by analysing two composition glass lines (Tl2S)x(GeS2)100-x (0 ≤ x ≤ 50) and (Tl2S)10(GeS)x(GeS2)90-x (0 ≤ x ≤ 90) together with three thallium containing crystalline compounds Tl4Ge4S10, Tl4Ge2S6 and Tl4GeS4. The crystallization ability variation in the binary Tl2S-GeS2 system can be explained comparing the structural characteristics of glasses and closest crystalline compounds. The room temperature dc conductivity increases by 7 orders of magnitude with increasing thallium concentration and reaches the value of 10-8 S cm-1 for (Tl2S)50(GeS2)50 sample. Combined with thallium diffusion parameters for (Tl2S)x(GeS)60(GeS2)40-x and (Tl2S)x(GeS)50-x/2(GeS2)50-x/2 composition lines as well as with conductivity characteristics for the crystalline analogues, ionic and electronic conductivities in the (Tl2S)x(GeS2)100-x glasses were estimated separately. The Tl-poor glasses (x ≤ 0.25) are essentially semiconductors, while the Tl-rich vitreous alloys appear to be ionic conductors. The conductivity parameters for (Tl2S)10(GeS)x(GeS2)90-x glasses change non- monotonically with GeS concentration passing by the conductivity minimum for 60% mol. GeS. The same behaviour was observed for thallium free (GeS)x(GeS2)100-x matrix, showing the influence of the GeS/GeS2 ratio on the properties of the thallium-poor semiconducting glasses.
关键词： glass formation,electrical transport,ionic conduction,Thallium thiogermanate glasses
更新于2025-09-23 15:21:01
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Photoluminescence properties and energy transfer investigations of Gd3+ and Sm3+ co-doped ZnOa??BaOa??TeO2 glasses for solid state laser application
摘要： The physical, optical, photoluminescence properties of (54-x) TeO2 – 10ZnO – 35BaO –1Sm2O3 – xGd2O3, where 0 ≤ x ≤ 3 (mol %) are investigated in this research. Five samples of glass were produced by the normal melt quenching process. The evidence indicates that the density of glass increased with increasing of Gd2O3. The molar volume and refractive index investigations have been used to consider the physical properties and optical properties of the produced glass system. Physical parameters such as polaron radius, inter-ionic radius and field strength for Sm3+/Gd3+ ions have been evaluated. The absorption spectra of glass contain peaks at 358, 404, 948, 1,085, 1,235, 1,385, 1,490 and 1535 nm corresponding to the transitions from 6H5/2 to 4D3/2, 6P3/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, and 6H15/2, respectively. The emission spectra of glass show four bands at found and attributed to 563, 604, 646 and 709 nm by excitation at 275 nm. Judd-Ofelt parameters and radiative properties was investigated for 53.5TeO2 – 10ZnO – 35BaO – 1Sm2O3 – 0.5Gd2O3 glass. Energy transfer characteristics was observed in the present glasses. The emission intensity of Sm3+ increased with increasing of Gd2O3 concentration until 2 mol %, while the luminescence lifetime decreases with increasing of Gd2O3 content.
关键词： Sm3+ ion,Tellurite glass,Gd3+ ion,Energy transfer
更新于2025-09-23 15:21:01
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Copper nanoparticles enhanced luminescence of Eu3+ doped lead tellurite glass ceramics
摘要： Structural, optical and magnetic properties of some lead tellurite glass ceramics doped with europium(III) ions and co-doped with fixed amounts of metallic copper nanoparticles (CuNPs) or copper(II) ions (via CuO) were investigated. Samples in the (Eu2O3)x·(TeO2)80·(PbO)(19.7-x)·(CuNPs)0.3 and (Eu2O3)x·(TeO2)80·(PbO)(19.7-x)·(CuO)0.3 systems with 0 ≤ x ≤ 10 mol% were obtained and investigated for the first time. Several techniques such as X-ray diffraction, UV-VIS, EPR and luminescence spectroscopies and density and magnetic susceptibility measurements were used in order to characterize the samples. XRD data show that the samples with low Eu2O3 contents (x ≤ 1 mol%) are amorphous while for higher europium oxide contents (x > 1 mol%) are glass ceramics. They also reveal that increasing the Eu2O3 content of samples the symmetry around the europium ions changes from face centered cubic to monoclinic. These symmetry changes are confirmed by the photoluminescence data. In addition, photoluminescence data show that the co-doping with metallic copper nanoparticles enhances the emission peaks of europium ions. UV-VIS absorption spectra show the presence of six coordinated copper (II) ions located at sites with a distorted octahedral symmetry. The EPR data confirm the presence of copper (II) ions in all the studied samples. Magnetic susceptibility measurements suggest the presence of europium ions in both their 3+ and 2+ valence states and evidence an important clustering tendency of europium ions even for low Eu2O3 contents.
关键词： EPR,UV-VIS,Photoluminescence,Magnetic susceptibility,Lead-tellurite glass ceramics,XRD
更新于2025-09-23 15:21:01
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Performance and stability enhancement of Cu(InGa)Se2 solar cells on ultrathin glass by potassium incorporation
摘要： Flexible Cu(InGa)Se2 solar cells fabricated on metal foils and plastics have achieved high conversion efficiency so far. However, metal impurities and low temperature tolerance hinder them from further considerable development. Here, 150 lm-thick ultrathin glass with desirable advantages was applied as substrate for Cu(InGa)Se2 solar cell. Potassium element was doped by a simple method during the post-selenization process. The results showed that the KInSe2 phase existed in K-doped Cu(InGa)Se2 films. The K-doped CIGS films were more compact than the pristine one due to the fact that K incorporated in films could form quasi-liquid alkali-metal-Se compounds and improve the compactness of films. K-incorporated CIGS films exhibited enhanced p-type conductivity and different surface energy level. Consequently, K-doped Cu(InGa)Se2 solar cell achieved an optimal efficiency of 8.3%, which was relatively 43% higher than that of pristine solar cell. Investigation of performance and stability of solar cells manifested that the K incorporation retarded the performance degradation of device during cyclic bending.
关键词： Potassium incorporation,Ultrathin glass,Cu(InGa)Se2,Thin films,Solar energy materials
更新于2025-09-23 15:21:01
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Mid-infrared saturated absorption spectroscopy inside a hollow glass waveguide
摘要： We report the saturation spectroscopy of carbon dioxide inside a hollow glass waveguide (GW) using a tunable mid-infrared difference frequency generation (DFG) source. This DFG source was generated in a periodically poled lithium niobate crystal with a tuning range from 3.97 to 4.71 μm. Saturated spectroscopy was performed on the R(60) transition of CO20001 ← 0000 band at 4.2 μm inside a hollow GW of diameter 300 μm and length 1 m. The saturation dip signal was found with a pump power as low as 0.18 mW inside the hollow GW. The linewidth of the dip was determined to be 4.40 MHz.
关键词： Nonlinear optical interaction,Mid-infrared,Saturation spectroscopy,Hollow glass waveguide
更新于2025-09-23 15:21:01
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Optical characteristics of the undamaged and laser damaged K9 glass in terahertz band
摘要： K9 glass is an important optical element of the high energy laser system. In an attempt to investigate the variation of optical properties of K9 glass before and after laser induced damage, based on the transmission terahertz time-domain spectral system, the undamaged and the damaged K9 glasses induced by laser were tested to obtain the terahertz time-domain and frequency-domain spectra and the refractive index and absorption coef?cient of the samples were calculated in terahertz band for further analysis. Results show that with the increase of laser energy, from the undamaged to the damaged K9 glasses to different extent, the peak to peak value in time domain and the amplitude value in frequency domain present a decreasing trend in varying degrees, and in the 0.4～0.5 THz band, the absorption coef?cient increases continuously with a slight change of refractive index, which indicates that K9 glass not only appears the melting and fracture in the macroscopic morphology after laser-induced damage, but also forms non-bridged oxygen atoms in its microstructure with more ion bonds and free electrons and the change of ion polarization. In this regard, this paper provides a technical basis for exploring the micro characteristics of K9 glass after laser-induced damage, and lays a good foundation for the application of terahertz time-domain spectroscopy to laser-induced damage analysis.
关键词： terahertz time-domain spectrum,K9 glass,laser-induced damage,refractive index,absorption coef?cient
更新于2025-09-23 15:21:01
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Modifying the thermomechanical properties of electrospun fibres of poly-vinyl cinnamate by photo-cross-linking
摘要： We explore the effects of cross-linking on some thermal and mechanical properties of polymer nanofibers of poly-vinyl cinnamate which were electro-spun from 1,2 dichloroethane. Scanning electron microscopy performed on the fibres revealed smooth fibres which were devoid of beading or ribbon-type features. When cross-linked, the Young’s moduli and glass transition temperatures of the fibres increase, owing to the formation of new covalent bonds which leads to higher overall binding energies. The glass transition temperatures increased by 20 K after 1 h of photo-polymerization while the Young’s modulus increased by 50% for the same exposure time. The glass transition temperatures as well as the heats of enthalpy indicate that a significant portion of cross-linking occurs within the first 10 min of exposure.
关键词： Photo-polymer,Young’s modulus,Enthalpy,Glass transition,Electro-spinning,Cross-linking
更新于2025-09-23 15:21:01