Si Glass Research Articles

Synchrotron Near-Field Infrared Nanospectroscopy and Nanoimaging of Lithium Fluoride in Solid Electrolyte Interphases in Li-Ion Battery Anodes.

Lithium fluoride (LiF) is a ubiquitous component in the solid electrolyte interphase (SEI) layer in Li-ion batteries. However, its nanoscale structure, morphology, and topology, important factors for understanding LiF and SEI film functionality, including electrode passivity, are often unknown due to limitations in spatial resolution of common characterization techniques. Ultrabroadband near-field synchrotron infrared nanospectroscopy (SINS) enables such detection and mapping of LiF in SEI layers in the far-infrared region down to ca. 322 cm-1 with a nanoscale spatial resolution of ca. 20 nm. The surface sensitivity of SINS and the large infrared absorption cross section of LiF, which can support local surface phonons under certain circumstances, enabled characterization of model LiF samples of varying structure, thickness, surface roughness, and degree of crystallinity, as confirmed by atomic force microscopy, attenuated total reflectance FTIR, SINS, X-ray photoelectron spectroscopy, high-angle annular dark-field, and scanning transmission electron microscopy. Enabled by this approach, LiF within SEI films formed on Cu, Si, and metallic glass Si40Al50Fe10 electrodes was detected and characterized. The nanoscale morphologies and topologies of LiF in these SEI layers were evaluated to gain insights into LiF nucleation, growth, and the resulting nuances in the electrode surface passivity.

Casimir Interaction of Chern–Simons Layers on Substrates via Vacuum Stress Tensor

We develop a Green’s functions scattering method for systems with Chern–Simons plane boundary layers on dielectric half-spaces. The Casimir pressure is derived by evaluation of the stress tensor in a vacuum slit between two half-spaces. The sign of the Casimir pressure on a Chern–Simons plane layer separated by a vacuum slit from the Chern–Simons layer at the boundary of a dielectric half-space is analyzed for intrinsic Si and SiO2 glass substrates.

Preparation and Characterization of Low- emissivity AlN/Ag/AlN Films by Magnetron Cosputtering Method

AlN and Ag thin films were deposited independently on the Si(100) wafers and glass slides by sputtering techniqueat various times to find the optimum deposition times for coating AlN and Ag films layers. The results obtained fromglazing-incident X-ray diffraction (GIXRD), field-emission scanning electron microscopy (FE-SEM), and transmittancemeasurements showed that the optimum deposition time for coating AlN and Ag film layers were 40 min and 15 scorresponding to the film thickness of 46.7 and 19.6 nm, respectively. The optimum deposition times were used forcoating AlN and Ag films in the multilayer AlN/Ag/AlN film stack. Then, the multilayer AlN/Ag/AlN film stack wasdeposited on the glass slide for transmittance measurement and a test glass plate with a size of 10 cm x 10 cm for infraredprotection testing. The average solar transmittances in the visible range ( = 380-780 nm) and in the near infrared range( = 780-2,000 nm) were found to be 48.05 and 15.17%, respectively which are comparable with those of a commercialglass.

Opto-electronic properties of Zr[formula omitted]Hf[formula omitted]O[formula omitted]/Al/Zr[formula omitted]Hf[formula omitted]O[formula omitted] thin-films: The influence of substrate temperature

The influence of substrate temperature on ZrxHf1−xO2/Al/ZrxHf1−xO2 trilayer thin-films deposited on n-type Si(100) and commercial glass substrates using magnetron sputtering technique is systematically investigated with the substrate temperature ranging from 25 to 300°C. The deposited films are characterized by x-ray reflectivity (XRR), grazing incidence x-ray diffraction (GI-XRD), x-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), cross-sectional transmission electron microscope (TEM), energy-dispersive x-ray spectroscopy (EDX) and UV–VIS spectroscopy to study the microstructural, morphological and optical properties. Capacitance–voltage (C–V) and current–voltage (I–V) measurements are performed to investigate the electrical properties of the trilayer thin-films. Physical characterization reveals that as the substrate temperature rises, the crystalline quality of the trilayer thin-films improves. Further, a rise in substrate temperature causes an increase in surface roughness and grain size. The trilayer thin-film deposited at 300°C shows improved optical transmittance over wavelengths 400–1100 nm. In addition this trilayer thin-film demonstrates highest figure of merit, lower leakage current as well as improved breakdown performance. Hence, ZrxHf1−xO2/Al/ZrxHf1−xO2 thin-film prepared at 300°C could be used in opto-electronic devices.

Erbium–bismuth-doped germanium silicate active optic glass for broad-band optical amplification

This work deals with research and optimization of the optical Ge–Si glass composition doped with Er3+, Yb3+ ions and bismuth optically active centers (BACs), which are optically active for implementation in a double C- and U-band planar optical amplifier. The intention was to increase the range of amplified wavelengths in the NIR band up to 1650 nm. Various types of glass with different content of GeO2, SiO2 and Er2O3, Yb2O3 ions Bi2O3 were prepared and the luminescence response in the 1500–1700 nm range was tested. The maxima of the luminescence intensity in the optical bands and the spectral full width at half maximum (FWHM) were determined by modified reflex spectrum method measurement. The prepared Ge–Si glass doped with Er3+ ions and BACs exhibited strong and balanced emission in the 1520–1680 nm range after pumping at 1480 nm. The specific balanced differential gain of up to 0.2 dB/cm in the C-band and simultaneously 0.2 dB/cm in the U-band was measured. Our results proved that the luminescence of BACs depends on the presence of optical active Er3+ ions and germanium in matrix of glass, pumped by radiation 1480 nm and energy transfer from erbium to BACs have been newly observed in the Ge–Si glass. It has also been found that high content of germanium, comparable with silicon content is required for this transfer. The results show that the germano-silicate glass doped with Er3+ and Bi ions is a perspective material for the fabrication of broad-band amplifiers in the C- and U-bands.

An On-Chip Microscale Vacuum Chamber with High Sealing Performance Using Graphene as Lateral Feedthrough.

On-chip microscale vacuum chambers with high sealing performance and electrical feedthroughs are highly desired for microscale vacuum electronic devices and other MEMS devices. In this paper, we report an on-chip microscale vacuum chamber which achieves a high sealing performance by using monolayer graphene as lateral electrical feedthrough. A vacuum chamber with the dimensions of π × 2 mm × 2 mm × 0.5 mm is fabricated by anodically bonding a glass chip with a through-hole between two Si chips in a vacuum, after monolayer graphene electrodes have been transferred to the surface of one of the Si chips. Benefiting from the atomic thickness of monolayer graphene, the leak rate of Si-glass bonding interface with a monolayer graphene feedthrough is measured at less than 2 × 10-11 Pa·m3/s. The monolayer graphene feedthrough exhibits a minor resistance increase from 22.5 Ω to 31 Ω after anodic bonding, showing good electrical conductance. The pressure of the vacuum chamber is estimated to be 185 Pa by measuring the breakdown voltage. Such a vacuum is found to maintain for more than 50 days without obvious degradation, implying a high sealing performance with a leak rate of less than 1.02 × 10-16 Pa·m3/s.

Evaluation of thin film material properties using a deep nanoindentation and ANN

Due to the substrate effect, there are several difficulties to evaluate the material properties of thin films via nanoindentation. In this study, an inverse analysis method based on an artificial neural network (ANN) is proposed to obtain free-volume-model (FVM) parameters of thin film metallic glass (TFMG) via nanoindentation. Unlike conventional nanoindentation procedures for thin films, a deeper indentation depth (≈ 30% of film thickness) is adopted to accurately identify the film properties even with significant substrate deformations. Both sphero-conical and Berkovich tips are employed to ensure unique solutions. A complex mapping function of inverse analysis is replaced by establishing ANN between nanoindentation (features) and material (targets) parameters. The established ANN model is trained with the database generated via systematic finite element analyses (FEA). The trained ANN model is experimentally validated by estimating the material properties of Zr55Cu30Ag15 TFMG deposited on two different substrates (Si and soda lime glass). The maximum difference of plastic indentation energy between experiments and FEA values using the estimated film material properties was within 3%.

Effects of Li–B–Si–Ca–Mn glass addition on the densification, microstructure, and dielectric properties of (Ca,Sr)(Zr,Ti)O3 ceramics

Finding a suitable sintering aid to lower the sintering temperature of the dielectric material is important for making multilayer ceramic capacitors (MLCCs) with copper electrodes. In this study, Li–B–Si–Ca–Mn (LBSCM) glasses were prepared by melt quenching with the addition of an anti-reduction agent as a sintering aid for (Ca0.7Sr0.3)(Zr0.97Ti0.03)O3 dielectric ceramics (CSZT). Based on the defect chemistry and interaction between CSZT and LBSCM glass, the effects of the Li–B–Si glass addition on the sintering, microstructure, and dielectric properties of CSZT were investigated. It was found that the addition of 5 wt% LBSCM glass resulted in a dense microstructure after sintering at a temperature range of 975 °C–1100 °C in 99%N2–1%H2. The capacitance at 1 MHz between 140 and 150 pF, loss of about 0.19%, the breakdown voltage of about 1050 V, insulation resistance around 1011 Ω were obtained for the MLCCs with the size of 0805 using the CSZT added with 5 wt% LBSCM glass as the raw material and copper as the inner electrode sintered at 1000 °C for 1 h and 3 h under a reduction atmosphere of 1% H2/99% N2 mixture gas. This suggests that the CSZT added with 5 wt% LBSCM can be a good candidate as a dielectric material for MLCCs with copper electrodes.

Wafer-Level Self-Packaging Design and Fabrication of MEMS Capacitive Pressure Sensors.

This paper reports a MEMS capacitive pressure sensor (CPS) based on the operating principle of touch mode. The CPS was designed and fabricated using wafer-level self-packaged MEMS processes. The variable capacitance sensing structure was vacuum-sealed in a cavity using the Si–glass anodic bonding technique, and the embedded Al feedthrough lines at the Si–glass interface were used to realize the electrical connections between the parallel plate electrodes and the electrode pads through Al vias. The optimal design of the CPS structure was performed to trade-off the performance and reliability using finite element simulation. The CPS based on a circular-shaped diaphragm with a radius of 2000 µm and a thickness of 40 µm exhibits good comprehensive performance with a sensitivity of 52.3 pF/MPa and a nonlinearity of 2.7%FS in the pressure range of 100–500 kPa when the ambient temperature is less than 50 °C.

Effect of annealing temperature on properties of WS2 thin films

ABSTRACT In this paper, the influences of different annealing temperature from 200 to 500°C with an interval of 100°C on the properties of WS2 thin films deposited onto the Si substrates and glass substrates prepared through RF magnetron sputtering were investigated. The optical and electrical properties were tested using Ultraviolet Spectrophotometer and Hall Tester, respectively. The results show that the properties of WS2 thin films did not change linearly with temperature, WS2 thin films obtained the optimal electron mobility of 1.69 × 103 cm2/Vs, the optimal bulk carrier concentration of 1.28 × 1018 cm−3, the smallest band gap of 1.5 eV, and the smallest resistivity of 5.77 × 10−2 Ω−1·cm−1 at 400°C. Moreover, the S/W was close to the ideal WS2 stoichiometric of 2.

Corrigendum to “Enhanced interfacial wettability change materials based on graphene-doped Pb–Te–Si glass frit for wide sintering window of solar cells” [226, 1 July 2021, 111049

Corrigendum to “Enhanced interfacial wettability change materials based on graphene-doped Pb–Te–Si glass frit for wide sintering window of solar cells” [226, 1 July 2021, 111049

Wafer-Level 3D Integration Based on Poly (Diallyl Phthalate) Adhesive Bonding

Three-dimensional integration technology provides a promising total solution that can be used to achieve system-level integration with high function density and low cost. In this study, a wafer-level 3D integration technology using PDAP as an intermediate bonding polymer was applied effectively for integration with an SOI wafer and dummy a CMOS wafer. The influences of the procedure parameters on the adhesive bonding effects were determined by Si–Glass adhesive bonding tests. It was found that the bonding pressure, pre-curing conditions, spin coating conditions, and cleanliness have a significant influence on the bonding results. The optimal procedure parameters for PDAP adhesive bonding were obtained through analysis and comparison. The 3D integration tests were conducted according to these optimal parameters. In the tests, process optimization was focused on Si handle-layer etching, PDAP layer etching, and Au pillar electroplating. After that, the optimal process conditions for the 3D integration process were achieved. The 3D integration applications of the micro-bolometer array and the micro-bridge resistor array were presented. It was confirmed that 3D integration based on PDAP adhesive bonding is suitable for the fabrication of system-on-chip when using MEMS and IC integration and that it is especially useful for the fabrication of low-cost suspended-microstructure on-CMOS-chip systems.

Microfluidic Bioreactor Made of Cyclo-Olefin Polymer for Observing On-Chip Platelet Production.

We previously proposed a microfluidic bioreactor with glass–Si–glass layers to evaluate the effect of the fluid force on platelet (PLT) production and fabricated a three-dimensional (3D) microchannel by combining grayscale photolithography and deep reactive ion etching. However, a challenge remains in observing the detailed process of PLT production owing to the low visibility of the microfluidic bioreactor. In this paper, we present a transparent microfluidic bioreactor made of cyclo-olefin polymer (COP) with which to observe the process of platelet-like particle (PLP) production under a bright-field, which allows us to obtain image data at a high sampling rate. We succeeded in fabricating the COP microfluidic bioreactor with a 3D microchannel. We investigated the bonding strength of COP-COP layers and confirmed the effectiveness of the microfluidic bioreactor. Results of on-chip PLP production using immortalized megakaryocyte cell lines (imMKCLs) derived from human-induced pluripotent stem cells show that the average total number of produced PLPs per imMKCL was 17.6 PLPs/imMKCL, which is comparable to that of our previous glass–Si–glass microfluidic bioreactor (17.4 PLPs/imMKCL). We succeeded in observing PLP production under a bright-field using the presented microfluidic bioreactor and confirmed that PLP fragmented in a narrow area of proplatelet-like protrusions.

Optical properties and energy transfer probing for white light emission in Ce3+/Tb3+/Sm3+ tri-doped barium gallium borosilicate glasses

Switching of three trivalent ions in a host glass may tailor the emission properties. In this direction, singly Ce3+, Tb3+, Sm3+ doped and Ce3+/Tb3+/Sm3+ tri-doped barium gallium borosilicate (CTS) glasses were synthesized and spectroscopic studies viz., optical absorption and photoluminescence were performed to investigate the emission properties. The amorphous nature, thermal stability and functional groups in the glass are identified by x-ray diffraction, differential thermal analysis (DTA), FTIR spectra, respectively. The optical absorption (OA) spectra of triply doped glasses have shown Ce3+ion transition 4f (2FJ) → 5d (2A1g) at 416 nm, four bands from 7F6 ground state of Tb3+ ions and nine bands from 6H5/2 ground state in the visible and NIR regions of Sm3+ ions. The evaluated values of optical band gap (Eg) have shown inverse proportionality with Ce3+ ion concentration in Tauc plots and correlated with optical basicity of glasses. The photo luminescence (PL) spectra of Ce3+/Tb3+/Sm3+ tri-doped Ba Ga B Si glass with 0.6 mol % Ce3+ ions (0.6 CTS) have shown maximum emission when excited at 350 nm. The energy transfer (ET) mechanism with dipole-dipole as main interaction between Ce3+ → (Tb3+→ Sm3+) ions is evident from all non-exponential time decay curves fitted with I–H (Inokuti-Hirayama) model. The ET efficiency ‘η’ is varied from 36.8 to 57.6 %. The colour chromaticity coordinates at 350 nm excitation and emission covered blue (Ce), reddish orange (Sm) and green (Tb) regions. The CCT values of glasses are varying from 1636 K to 6412 K provides the scope for white LED applications.

Hydrothermal Co-Processing of Coal Fly Ash Cenospheres and Soluble Sr(II) as Environmentally Sustainable Approach to Sr-90 Immobilization in a Mineral-like Form.

Co-processing of radioactive effluents with coal fly ash-derived materials is recognized as a resource-saving approach for efficient stabilization/solidification of radioactive components of wastewater. In this context, the paper is focused on the hydrothermal synthesis of Sr2+-bearing aluminosilicate/silicate phases as analogs of a mineral-like 90Sr waste form using hollow glass-crystalline aluminosilicate microspheres from coal fly ash (cenospheres) as a glassy source of Si and Al (SiO2-Al2O3)glass) and Sr(NO3)2 solutions as 90Sr simulant wastewater. The direct conversion of cenosphere glass in the Sr(NO3)2-NaOH-H2O-(SiO2-Al2O3)glass system as well as Sr2+ sorption on cenosphere-derived analcime (ANA) in the Sr(NO3)2-H2O-ANA system were studied at 150–200 °C and autogenous pressure. The solid and liquid reaction products were characterized by SEM-EDS, PXRD, AAS and STA. In the Sr(NO3)2-NaOH-H2O-(SiO2-Al2O3)glass system, the hydrothermal processing at 150–200 °C removes 99.99% of the added Sr2+ from the solution by forming Sr-tobermorite and Sr-plagioclase phases. In the Sr(NO3)2-H2O-ANA system, Sr2+ sorption on analcime results in the formation of solid solutions (Na1−nSrn/2)AlSi2O6·H2O of the Na-analcime–Sr-wairakite series. The results can be considered as a basis for the development of environmentally sustainable technology for 90Sr removal from wastewater and immobilization in a mineral-like form by co-processing waste from coal-fired and nuclear power plants.

Effects of Substrates on Structural and Morphological Characteristics of Radio Frequency Sputtered ZnO Layers

High quality Zinc Oxide nanostructures (ZONSs) with customized traits became demanding for diverse applications. Based on this fact, some ZONSs with varied layer thicknesses (100 to 400 nm) were deposited on three types of Si (plain, polished and etched) and borosilicate glass substrates using the radio frequency (RF) sputtering method. Asdeposited samples were characterized systematically using various techniques to determine the effects of the substrates on their structures and morphologies. The XRD analyses of the sample showed the formation of high quality nanocrystallites with varying sizes where the crystallinity was improved with the increase of layer thickness and change of substrates. The FESEM and AFM images exhibited the nucleation of dense nanocrystallites with some pores/voids with enhanced surface roughness. In addition, the EDX spectra displayed the presence of appropriate chemical elements in the ZONSs layers. Sample grown on the etched Si substrate at layer thickness of 300 nm was found to be optimum. The results for the etched Si were presented. It was demonstrated that by optimizing the RF sputtering parameters (power of 100 W, Argon flow of 10 sccm and pressure of 10-5 mb) the structural and morphological traits of the layered ZONSs can be tailored. The proposed ZONSs may be useful for various optoelectronic applications including the metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors fabrication.

Magnetically Driven Non‐Contact Transfer Printing Based on a Bi‐Stable Elastomeric Stamp

AbstractTransfer printing that enables the heterogeneous integration of a variety of materials in desired 2D or 3D layouts is essential for developing existing and envisioned systems such as flexible electronics, stretchable electronics, and micro LED displays. Here, a simple yet robust magnetically driven non‐contact transfer printing technique based on a bi‐stable elastomeric stamp is reported. This stamp features adhesive blocks, a magnetic‐response film with a buckled configuration and a cavity. The magnetic‐response film can be controlled with a rapid snap‐through under a magnetic field to switch interfacial adhesion from strong state for reliable pick‐up to weak state for easy printing, which allows the printing of inks onto arbitrary receivers. Experimental, numerical, and theoretical studies reveal the fundamental aspects of design and operation of the stamp to enable a highly efficient non‐contract transfer printing technique. Demonstrations of this concept in transfer printing of Si platelets, papers, pearl cottons, glass slides, and porous acrylic plates onto various challenging non‐adhesive receivers (e.g., cleanroom wiper, cloth, leather, glass, or paper) illustrate its robust capabilities in manipulation of objects with a wide range of materials and its great potential for deterministic assembly, thereby creating engineering opportunities in applications requiring the heterogeneous integration of diverse materials.

An In Situ Film-to-Film Transformation Approach toward Highly Crystalline Covalent Organic Framework Films

An In Situ Film-to-Film Transformation Approach toward Highly Crystalline Covalent Organic Framework Films

Enhanced interfacial wettability change materials based on graphene-doped Pb–Te–Si glass frit for wide sintering window of solar cells

Glass frits play an essential role in the front silver paste of solar cells. In this study, we prepared a new type of graphene-doped glass frit by hydrothermal reaction. Brunauer-Emmett-Teller (BET) indicates that the doped glass frit has a smaller particle size and a larger surface area, which promotes front contact metallization. Appropriate contact angles and high-temperature microscopy (HSM) result in excellent wettability, a wide sintering window and etching effects. Graphene-doped multicrystalline silicon solar cells have better photoelectric conversion efficiency (19.10%) that is 0.6% higher than solar cells using traditional glass frits. Through characterization, we further found a large amount of conductive alloy and Ag at the interface, which facilitates electron flow. Therefore, an excellent ohmic contact is formed between the electrode and the n+ emitter, which reduces the contact resistance of the solar cell. This research has prospective guiding significance for the development of new high wettability glass frits for commercial multicrystalline silicon solar cells in the future.

Relationship between structure, surface topography and tribo-mechanical behavior of Ti-N thin films elaborated at different N2 flow rates

Titanium nitride films were deposited by reactive magnetron sputtering on Si (100) wafers, glass and Ti6Al4V substrates. The film deposition was carried out in a gas mixture of Ar and N2. The nitrogen content was varied between 0 and 30 % of the total gas mixture. This variation led to the formation of different films with different microstructures. The microstructure of the Ti-N coatings presented nanocomposites with a low tendency to surface oxidation. From a pure Ti to tetragonal Ti2N and cubic Ti-N microstructures, the films showed a (111) TiN plane growth that led to an increase in the lattice strain and a decrease in the grain size when increasing the nitrogen flow rate. The water-film contact angle measurements showed that the surface hydrophobicity increased with the increase of nitrogen content in the film. Mechanical properties were measured and a strong dependence between microstructure and hardness was found. The Ti-N deposited under 20 % of N2 exhibited the highest hardness, the best adhesion and wear resistance, and the lowest friction coefficient with the presence of (111) fiber texture.