In this paper, we show a novel method to obtain small size textures usable in crystalline silicon (c-Si) solar cells. SiO2-based glass microparticles are mixed with a conventional KOH-based alkaline solution for making the textures. Using this mixing method, the texture size can be drastically reduced from 10 to ≤2 µm (0.3–2 µm). In addition, the process time and c-Si loss during the texture formation are reduced from 25 to 2 min and from 20 to 2 µm, respectively. Thus, the process is applicable to c-Si with thickness down to 50 µm. High-quality passivation showing the effective minority carrier lifetimes (τeff) larger than several ms and effective antireflection coating are possible on the new textures. The process is named “microparticle-assisted texturing (MPAT) process”, and its features are also demonstrated.

The electrochemical technique has been used to prepare aluminum-doped zinc oxide (AZO) films on FTO substrates using zinc nitrate and aluminum chloride precursor solution at 70 °C. The crystal structure, surface morphology, optical and electrical features of AZO films were examined at different potential voltages from −1.7 to −2.3 V in the initial solution. Structural studies of the deposited films were carried out through X-ray diffraction; the AZO films exhibited a polycrystalline nature with hexagonal structure, and crystals preferentially grew along the (002) orientation. The morphology of the deposited films was characterized by scanning electron microscopy (SEM), and the images showed that the spherical- and nanorod-shaped particles are uniformly distributed on the entire AZO film surface. The average size is found to be in the range of 45–70 nm by SEM and 28–32 nm by using the Scherrer’s rule. The EDS spectrum confirmed the chemical composition of Zn, O, Al, Sn, and F elements over the film surface. The optical properties were studied using a UV-visible spectrophotometer, and the deposited film showed the highest optical transmittance of ∼80% in the visible range for −1.7 V. The calculated energy gap of the AZO films decreases from 3.09 to 2.97 eV with increasing potential voltages. AZO thin films have been studied using photoluminescence to identify the film’s optical quality with respect to the wavelength range. The electrical properties were studied by the room temperature Hall effect system, and the observed low resistivity (ρ) is 1.58 × 10−2 (Ω cm) for the film deposited using a −2.1 V potential voltage.

Pure and magnesium-doped TiO2 nanoparticles (NPs) of three different concentrations (3, 6, and 9 mol%) were synthesized by a simple, cost effective solvothermal microwave irradiation method and characterized by XRD, EDAX, transmission electron microscopy (TEM), and UV-Vis diffuse reflection spectroscopy. X-ray diffraction studies performed on synthesized NPs have shown that the anatase phase is preserved after doping and the dopant does not change the crystalline phase (anatase) of the parent material (TiO2). TEM results revealed that the particle size was significantly reduced with increasing dopant concentration and are spherical in shape. For the J–V measurements, the devices were subjected to the simulated sun light of 100 mW/cm2 irradiation with a working electrode area of 0.25 cm2 (0.5 × 0.5 cm). The results show that the dye-sensitized solar cell based on a 3 mol% Mg-doped TiO2 electrode achieved a photoelectrical conversion efficiency of 7.36% which is perceptibly increased by 17.6% than undoped TiO2 (6.26%).

Nacre-mimetic (PE/TiO2)4 nanolayered composites (NLCs) with the nanocrystalline TiO2 layer thickness less than 30 nm and different thickness ratios of inorganic/organic layers were successfully prepared by using layer-by-layer self-assembly and chemical bath deposition method. Mechanical properties, especially fatigue properties of the NLCs with different thickness ratios were evaluated. The elastic modulus, hardness and fracture toughness, strain amplitude to fatigue limits of the NLCs reached 27.78 ± 5.69 GPa, 1.33 ± 0.31 GPa, and 4.16 ± 0.20 MPa m1/2, respectively. Fatigue performance of the NLCs in the high and low cycle fatigue regimes was optimized by tailoring the thickness ratio of the TiO2/PE layers. The PE/TiO2 NLCs with the larger thickness ratio of ∼3 has the high fatigue limit (the critical strain amplitude of 0.0853%) in the high-cycle fatigue regime, while that with the smaller thickness ratio of ∼1 and ∼0.5 are of the good fatigue strength in the low-cycle fatigue regime. The basic mechanism for the enhanced fatigue performance is elucidated.

Mastery of strengthening strategies to achieve high-capacity anodes for lithium-ion batteries can shed light on understanding the nature of diffusion-induced stress and offer an approach to use submicro-sized materials with an ultrahigh capacity for large-scale batteries. Here, we report solute strengthening in a series of silicon (Si)–germanium (Ge) alloys. When the larger solute atom (Ge) is added to the solvent atoms (Si), a compressive stress is generated in the vicinity of Ge atoms. This local stress field interacts with resident dislocations and subsequently impedes their motion to increase the yield stress in the alloys. The addition of Ge into Si substantially improves the capacity retention, particularly in Si0.50Ge0.50, aligning with literature reports that the Si/Ge alloy showed a maximum yield stress in Si0.50Ge0.50. In situ X-ray diffraction studies on the Si0.50Ge0.50 electrode show that the phase change undergoes three subsequent steps during the lithiation process: removal of surface oxide layer, formation of cluster-size Lix(Si,Ge), and formation of crystalline Li15(Si,Ge)4. Furthermore, the lithiation process starts from higher index facets, i.e., (220) and (311), then through the low index facet (111), suggesting the orientation-dependence of the lithiation process in the Si0.50Ge0.50 electrode.

In the recent past, two-dimensional (2D) nanocrystalline (NC) transition metal dichalcogenides such as MoS2 received a great deal of attention due to their extraordinary physical properties. There has been a great interest to study the defects present in MoS2 NCs, which alter the material’s catalytic, electrical, and magnetic properties. This work reports paramagnetic point defects present in the hydrothermally grown 2H–MoS2 NCs. X-band electron spin resonance (ESR) spectroscopy has been used to identify the defects which contain unpaired electron spins in the as-prepared and Ar-annealed MoS2 NCs. At least seven ESR signals were detected originating from four inequivalent paramagnetic defect sites such as adsorbed oxygen species, sulfur vacancies, thio-, and oxo-Mo5+. Upon Ar-annealing, most of these defects did not survive, instead conduction ESR signal was observed. This work signifies the importance of employing ESR spectroscopy and broadens the knowledge in identifying the atomic defects in MoS2 NCs.

Induced pluripotent stem cells (iPSCs) offer the possibility to accelerate tissue reconstruction through cell differentiation. The use of iPSCs in bone tissue engineering is promoted by next generation scaffolds which guide bone tissue repair and provide specific cues and molecular recognition to enhance differentiation as well as the bone forming ability of these cells. However, bone tissue repair faces additional challenges such as requirement for a consequent bone vasculature and exhaustion of stem cells in the aging adults. In this context, iPSC reprogramming seems to be unaffected by age and they have better pro-angiogenic potential as well as proliferation rate. The benefits of iPSCs using polymeric scaffolds include access to humanized in vitro models, triggering bone tissue reconstruction through a supply of bone cells via differentiation, compensating mesenchymal stem cells age-related deficiencies in osteodegenerative diseases, and enhancing angiogenesis.

In this study, nano-hydroxyapatite (n-HAp) of average crystallite size ∼8.15 ± 4 nm of hexagonal geometry with size ranging between 14 and 50 nm was synthesized in laboratory at room temperature by using suitable sources of calcium and phosphate ions and using triethanolamine. Mesoporous bioactive glass (MBG) was synthesized by using cationic surfactant cetyl trimethyl ammonium bromide of the SiO2–CaO–P2O5 glass system. After calcination at 650 °C, MBG powders were having a zeta potential of −16.5 mV (pH ∼9.1), median particle size ∼75 nm, and specific surface area 473.2 m2/g. An aqueous suspension of DNA was used to disperse both n-HAp and MBG and further subjected for analysis including absorbance, circular dichroism spectroscopy, UV-melting, and isothermal titration calorimetry. Absorbance spectroscopy indicated that an equilibrium binding was obtained between both materials and DNA in solution phase. Due to the addition of the nanomaterial, molar ellipticity of DNA was changed revealing that the materials were interacted with DNA. From UV melting characterization, there is a shifting of the melting temperature of DNA in the presence of MBG and n-HAp, respectively, suggesting that the nanoparticles stabilized DNA helix to a considerable extent.

In this project, we described the production of chrysin-loaded L-phenyl alanine (Phe)-coated iron oxide magnetic nanoparticles (chrysin@Phe@IOMNs). chrysin@Phe@IOMNs were characterized by X-ray diffraction, thermogravimetric analysis, fourier transform infrared spectroscopy, vibrating sample magnetometer, and transmission electron microscopy techniques. Next, hemocompatibility and biocompatibility of Phe-coated IOMNs were determined by hemolysis and MTT assays on HFF-2 and HEK-293 cell lines, respectively. Finally, the anticancer activity of chrysin@Phe@IOMNs was examined on MCF-7 cell line. The outcomes direct that as-prepared nanocarriers are nontoxic and biocompatible and also chrysin@Phe@IOMNs are appropriate for chrysin delivery and other hydrophobic therapeutic agents.

Manufacturing of advanced functional materials should also rely on the green chemistry principles like utilization of natural renewable resources. Marine environment offers plenty of renewable raw materials like chitin and its derivative chitosan. The paper presents how urea treatment has influenced several textural, chemical, and electrocatalytic properties of N-doped activated carbons (N_ACs) obtained from chitosan and chitin. The materials were subjected to an activation procedure (with different activators) as well as nitrogenation by premixing the precursors with water solutions of urea. Raw and premixed precursors were carbonized in the temperature range of 700–800 °C. The urea treatment resulted in a spectacular increase in the nitrogen content by weight (up to 68%) and an improvement of the surface area (up to 42%) along with total/micro-/mezo-pore volume (up to 49%). Some urea-modified N_ACs were capable of reducing oxygen in an alkaline solution as effectively as a Pt-loaded carbon material. The highest number of electrons transferred to O2 molecule was found to be equal to 3.76 for a chitosan derived sample. This ability of chitosan and chitin derived N-rich activated carbons was studied by means of the method named rotating ring disc electrode.

In this work, activated carbon was modified by ammonium persulfate and used as the catalyst support for CO2 hydrogenation to methanol. Then CuO and/or ZnO were loaded on the support by a facile wet-impregnation method. The obtained CuZn/C, Cu/C, and Zn/C catalysts were characterized by a series of characterization techniques including N2 physisorption, X-ray diffraction (XRD), X-ray photoelectron (XPS), and scanning and transmission electron microscopies (SEM and TEM). XRD and XPS results showed that ZnO affected the reduction of Cu2+. The TEM results showed that Cu particles were 14–18 nm for the fresh catalysts CuZn/C and Cu/C. ZnO particles were too small to be identified by TEM. The used catalysts CuZn/C and Cu/C had particle sizes of 10–25 nm and 50–60 nm, respectively. The enhanced methanol synthesis performance by ZnO could be ascribed to the morphology effect and slowing down the Cu particles sintering during the reactions.

Laser-assisted material extrusion was used in this study to realize high-performance 3D printing of semicrystalline polymers. A CO2 laser device was simply integrated into a traditional fused deposition modeling printer to supply the laser. The sample’s surface temperature was changed by controlling the laser power during printing, and thus the interlayer shear strength and crystallinity could both be effectively controlled. By implementing the laser-assisted process, the optimal interlayer shear strength of poly(ether ether ketone) (PEEK) could be improved by more than 45%, and the degree of crystallinity of PEEK was simultaneously improved by up to 34.5%, which has approached to the typical crystallinity of 35%. Therefore, the process provides a very effective solution for additive manufacturing of semicrystalline materials and helps clearly to establish a controllable mapping relationship between the laser parameters and material properties.

Functionally graded materials (FGMs) in which the elemental composition intentionally varies with position can be fabricated using directed energy deposition additive manufacturing (AM). This work examines an FGM that is linearly graded from V to Invar 36 (64 wt% Fe, 36 wt% Ni). This FGM cracked during fabrication, indicating the formation of detrimental phases. The microstructure, composition, phases, and microhardness of the gradient zone were analyzed experimentally. The phase composition as a function of chemistry was predicted through thermodynamic calculations. It was determined that a significant amount of the intermetallic σ-FeV phase formed within the gradient zone. When the σ phase constituted the majority phase, catastrophic cracking occurred. The approach presented illustrates the suitability of using equilibrium thermodynamic calculations for the prediction of phase formation in FGMs made by AM despite the nonequilibrium conditions in AM, providing a route for the computationally informed design of FGMs.

The TiCxN1−x(001)/TiC(001) interface was studied by the first-principles method to provide the theoretical basis for developing TiCxN1−x/TiC coatings. The partial density of state (PDOS), charge density, charge density difference, and Mulliken population analysis were utilized to investigate the bonding nature and the electronic characteristic of the TiC0.25N0.75/TiC interface. The corresponding results indicate that the bonding nature at the interface is ionic and covalent characteristics, which also exist in bulk materials. The extreme similarity of PDOS among interfacial C, N, and Ti atoms and their bulk counterparts reveals that the electronic structure transition at the interface is smooth. The results of Mulliken population analysis and plots of charge density and charge density difference demonstrate that the charge increased for C in the TiC side is less than that for N in the TiC0.25N0.75 side, which reveals that the ionic bond in TiC0.25N0.75 is stronger than that in TiC. Therefore, TiC0.25N0.75 coating can be an alternative choice to combine with TiC coating in the actual production process of multilayer coatings.

Boron carbide (B4C) is an attractive material for numerous applications including vehicle armor, cutting tools, blasting nozzles, and abrasive powder, owing to its extreme hardness, high melting point, high Young’s modulus, and excellent thermoelectric properties. However, the application of B4C is limited by the high-temperature synthesis process. The present work aims to explore a low-temperature manufacturing process for synthesizing B4C with a small amount of free carbon. Poly(resorcinol borate) with an aromatic structure and high char yield was chosen as the aromatic polymeric precursor. A combination of Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy was performed to investigate the influences of the reaction temperature and holding time on the changes in the precursor microstructure. The results indicate that the rod-like structure of crystalline B4C is successfully synthesized at 600 °C, and the free carbon can be reduced to about 0.8 wt% in the final product. This is because the pyrolysis temperature controlled the carbon content of the B4C, which led to an enlarged contact domain between B2O3 and carbon, and a relatively low-temperature synthesis of B4C.

The wetting of Cu–19Ni–5Al alloy on Ni-coated WC–8Co substrates with different coating thicknesses was investigated, and the brazing of Ni-coated WC–8Co to SAE1045 steel was performed by using the Cu–19Ni–5Al alloy as the filler metal. All the Cu–19Ni–5Al/Ni-coated WC–8Co systems present excellent wettability with a final contact angle of ∼10°. The thicknesses of the β + γ phase enriched with Co, Ni, and Al at the two joint interfaces increase and decrease with the Ni coating thickness, brazing temperature, and holding time increasing, respectively. The joint shear strength increases first and then decreases with the increase of Ni coating thickness, brazing temperature, or holding time. The maximum joint shear strength of ∼328 MPa is obtained while Ni plating for 90 min and brazing at 1210 °C × 5 min.

To prepare high quality large solidified Al2O3/ZrO2 eutectic ceramic, the preparation processing of the presintered ceramic as a feed rod was investigated via experiments; some parameters of the induction heating zone process were optimized via numerical modeling; an Al2O3/ZrO2 eutectic ceramic rod with a diameter 10 mm was prepared. The results show that increasing the sintering temperature could increase the presintered ceramic’s bulk density, while increasing sintering time had little effect. And the bulk density increased first and then decreased with the molding pressure increase. And the saucer coil obtained a higher temperature gradient than the tubbiness coil for a fixed crucible wall maximum temperature, and the coil turn’s increase could increase the melting zone height in the induction zone melting process. In the directionally solidified Al2O3/ZrO2 eutectic ceramics, Al2O3 phase is the matrix phase, and the ZrO2 phase embedded in the Al2O3 phase mostly with the rod shape, and little with lamellar. The hardness of directionally solidified eutectic ceramics reaches 16.17 GPa and the fracture toughness reaches 4.76 MPa m1/2, which are 1.7 times and 1.5 times of the presintered eutectic ceramic, respectively.

Previously known to form only under high pressure synthetic conditions, here we report that the T′-type 214-structure cuprate based on the rare earth atom Tb is stabilized for ambient pressure synthesis through partial substitution of Pd for Cu. The new material is obtained in purest form for mixtures of nominal composition Tb1.96Cu0.8Pd0.2O4. The refined formula, in orthorhombic space group Pbca, with a = 5.5117(1) Å, b = 5.5088(1) Å, and c = 11.8818(1) Å, is Tb2Cu0.83Pd0.17O4. An incommensurate structural modulation is seen along the a axis by electron diffraction and high resolution imaging. Magnetic susceptibility measurements reveal long-range antiferromagnetic ordering at 7.9 K, with a less pronounced feature at 95 K; a magnetic moment reorientation transition is observed to onset at a field of approximately 1.1 T at 3 K. The material is an n-type semiconductor.