Partial shading of Cu(In,Ga)(Se,S)2 (CIGS) photovoltaic (PV) modules is getting more attention, as is witnessed by the increase in publications on this topic in recent years. This review will give an overview of shading tests executed on CIGS modules and focuses on the more fundamental aspects that are often studied on cells. Generally, CIGS modules display very attractive performance under predictable row-to-row shading. However, potential damage could occur under nonoptimal shading orientations: module output after shading tests could reduce due to the formation of local shunts, often called wormlike defects. The influence of many factors on the formation of these defects, including the internal currents and voltages and the shape and intensity of the shade, will be discussed. This review allows an increased insight in the degradation mechanisms caused by partial shading, which would ultimately lead to the introduction of more shade-tolerant CIGS PV products in the future.

Cadmium telluride (CdTe) is one of the leading photovoltaic technologies with a market share of around 5%. However, there still exist challenges to fabricate a rear contact for efficient transport of photogenerated holes. Here, etching effects of various iodine compounds including elemental iodine (I2), ammonium iodide (NH4I), mixture of elemental iodine and NH4I (I−/I3− etching), and formamidinium iodide were investigated. The treated CdTe surfaces were investigated using Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The CdTe devices were completed with or without treatments and tested under simulated AM1.5G solar spectrum to find photoconversion efficiency (PCE). Based on Raman spectra, XRD patterns, and surface morphology, it was shown that treatment with iodine compounds produced Te-rich surface on CdTe films, and temperature-dependent current–voltage characteristics showed reduced back barrier heights, which are essential for the formation of ohmic contact and reduce contact resistance. Based on current–voltage characteristics, the treatment enhanced open-circuit voltage (VOC) up to 841 mV, fill factor (FF) up to 78.2%, and PCE up to 14.0% compared with standard untreated CdTe devices (VOC ∼ 814 mV, FF ∼ 74%, and PCE ∼ 12.7%) with copper/gold back contact.

Toroidal (ring-like) structures are common in organic chemistry, but at the nanoscale level, the inorganic nanorings and nanotori are limited and represented mainly by carbon, several p- and noble metals (Ag, Au, Al, and Au/Co/Au), metal and nonmetal oxides (ZnO, MoO2, Fe2O3, and SiO2), hydroxides (Co(OH)2), and salts (PbI2 and metal selenides), and some combinations of carbon nanotori with fullerenes and carbon chains, as well as doped nanorings, are known. The nanotori are closely related to ball-type nanostructures as nano-onions, nanoballs, and nanospheres. Despite their relative low existence, they possess several useful properties and respective applications as isolators, sensors, optoelectronics, as traps for atoms and ions, and counterparts in lubricants, thus causing a certain interest in their development. The properties of nanotori have been studied mainly by DFT calculations. Several nanorings possess stabilities up to 3000 K before unfolding, multiresonant properties and magneto–optical activity, paramagnetism, and ferromagnetism. The carbon nanorings are studied considerably better, being compared with other compounds. This review summarizes the state of the art of all available inorganic toroidal nanostructures, believing that a considerable higher number of inorganic systems might be prepared in this form, taking into account their unusual properties.

In order to develop an efficient and accurate quasi-continuum approach for contact problems of low-dimensional nanoscale carbon materials, a van der Waals contact-bond model is proposed in this study. This method can involve the important information of nano- and micro-structures, such as the bonded carbon atom interactions and the long-range van der Waals effect, which is usually homogenized and neglected in continuum methods. The degree of freedom of the atomic systems can be reduced dramatically; therefore, the model is beneficial for rapid simulations and large-scale computations of carbon nano-components. The so-called higher-order Cauchy–Born rule is used to establish the geometrically consistent constitutive model, and a meshless local Petrov–Galerkin-based computational framework is constructed for the mechanical responses of carbon nanoscale systems. The stiffness matrix is derived analytically, and the incremental governing equation is solved with the Newton–Raphson iteration method. Consequently, this method is much faster than order-N2 approaches such as molecular dynamic simulation.

The effects of silicon incorporation on the in vitro and in vivo properties of magnesium phosphate (MgP) bioceramics were studied. Samples were prepared by conventional solid state synthesis method. Scanning electron microscopy and micro-computed tomography (µ-CT) analysis showed that Si doping reduces degradability of MgP. In vitro studies have shown that MG63 cells can attach and proliferate on MgP samples. Live/dead imaging showed that MgP–0.5Si sample had highest cell proliferation, which was also quantitatively confirmed by alamar blue assay. In vivo biocompatibility of MgP ceramics was assessed after implantation in rabbit model. Detailed µ-CT analysis showed new bone tissue formation around the implant after 30 and 90 days. MgP–0.5Si ceramics had 84% bone regeneration compared with 56% for pure MgP ceramics, as confirmed by oxytetracycline labeling. Our finding suggests that Si doping can alter physicochemical properties of MgP ceramics and promotes osseointegration, which can be a useful choice for bone tissue engineering.

Chalcopyrite quantum dots (QDs) have emerged as a safe alternative to cadmium-based QDs for bio-applications. However, the research on AgInS2 chalcopyrite QDs has not been widely explored in terms of their toxicity. Herein, we report a synthesis of biocompatible AgInS2/ZnS QDs via a greener approach. The emission intensity of the as-synthesized AgInS2 core QDs was enhanced 2-fold after the ZnS shell growth. X-ray diffraction revealed the tetragonal crystal structure of QDs, and high-resolution transmission electron microscope images show that the QDs are spherical in shape and crystalline in nature. Cell viability assays conducted on different cell lines, such as HeLa, A549, and BHK-21 cells, indicated that AgInS2/ZnS QDs are least toxic at a QD concentration range of 100 µg/mL. The fluorescent microscope analysis of A549 cells incubated with AgInS2/ZnS QDs shows that the QDs were accumulated in the cell membranes. The as-synthesized AgInS2/ZnS QDs are less toxic and eco-friendly, and can be used for biolabeling.

In recent years, there has been a significant thrust toward the development of novel implant alloys based on β-Ti with low Young’s modulus to prevent stress shielding. In this study, porous Ti–Nb–Ta–Zr alloys with porosity of <55% and macro-pore size of 100–400 μm for biomedical applications were successfully fabricated by a space-holder method. The microstructure and compressive behavior were studied. The results show that the micro-pore size of porous Ti–Nb–Ta–Zr alloys decreases with an increase in the amount of the process control agent (PCA), which has no obvious effect on the porosity and the macro-pore size formed by the space holder. Porous Ti–Nb–Ta–Zr alloys fail mainly because of the cleavage and ductile fracture with some dimples in compression. The compressive modulus increases from 0.6 to 6.5 GPa with the increase in the PCA and decrease of the space holder. The influence mechanism has been analyzed by the finite element calculation and the Gibson–Ashby model.

Titanium (Ti) has been extensively used in medical devices owing to their low density, high strength, excellent corrosion resistance, and biocompatibility. However, thrombus formation and bacterial infections are still challenges for their application in specific clinical cases. Hence, we have developed a simple, efficient, and stable strategy that endow Ti with anticoagulant and antibacterial properties through chemical bonding and electrostatic bonding. A large number of hydroxyl groups were produced on the surface of Ti by annealing at 500 °C. Then, heparin was immobilized on annealed surface with chemical bonding and chitosan was captured in an electrostatically bound manner by simply soaking in solution. The results indicated that the surface-functionalized Ti exhibited excellent anticoagulant properties by a reduction in platelet adhesion and prolonged blood clotting time. Furthermore, the modified Ti also showed antibacterial properties against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

Macro-mesoporous zirconium titanate monoliths have been successfully prepared via a sol–gel process accompanied by phase separation, with poly(ethylene oxide) (PEO) as a phase separation inducer and N-methylformamide (NFA) as a gelation accelerator. The size and morphology of macropores are controlled by the PEO and NFA amount. By choosing appropriate starting composition, the co-continuous structure could be obtained. The as-dried gel is amorphous, the pore size is in the range of 0.05–0.5 μm, the porosity is 46%, and the surface area is 111 m2/g. After heat treatment at 500 °C, the gel transforms into the phase ZrTiO4, the macropore diameter decreases slightly, the porosity increases to 63%, and the surface area decreases to 40 m2/g. Moreover, the macroporous structure is well maintained, and the skeleton becomes dense and smooth. The samples have macropores, mesopores, and micropores before and after heat treatment.

Fe–6.5 Si–0.05 B alloy was used in the study to investigate the texture evolution and magnetic property of the ferromagnetic crystal under an axial high magnetic field during bulk solidification. Optical microscopy (OM) and X-ray diffraction (XRD) were applied to analyze the microstructures and texture evolution of the alloy solidified under different magnetic field intensities. The result shows that with an increase in the magnetic field intensity from 0 to 2 T, the texture gradually changes from random orientation to {100} 〈120〉, eventually becoming a mixture of cube and Goss texture. The alloys treated at 1 and 2 T showed magnetic anisotropic behavior, while the alloy treated at 0 T showed magnetic isotropic behavior. The change in magnetic property comes from the evolution of α-Fe crystal orientation. Furthermore, a method for controlling the crystallization process and crystallographic orientation by adjusting the magnetic field intensity was proposed.