Efficiency potential of crystalline Si solar cells is analyzed by considering external radiative efficiency (ERE), voltage, and fill factor losses. Crystalline Si solar cells have an efficiency potential of more than 28.5% by realizing ERE of 20% from about 5% and normalized resistance of less than 0.05 from around 0.1. Nonradiative recombination losses in single-crystalline and multicrystalline Si solar cells are also discussed. Especially, nonrecombination and resistance losses in multicrystalline Si solar cells are shown to be higher than those of single-crystalline cells. Importance of further improvement of minority-carrier lifetime in crystalline Si solar cells is suggested for further improvement of crystalline Si solar cells. High efficiency of more than 28.5% will be realized by realizing high minority-carrier lifetime of more than 30 ms. Key issues for those ends are reduction in carbon concentration of less than 1 × 1014 cm−3, oxygen precipitated and dislocations even in single-crystalline Si solar cells, and reduction in dislocation density of less than 3 × 103 cm−2 in multicrystalline Si solar cells.

Solution-processed metal oxide electronics on flexible substrates can enable applications from military to health care. Due to limited thermal budgets and mismatched coefficients of thermal expansion between oxides and substrates, achieving good performance in solution-processed oxide films remains a challenge. Additionally, the use of traditional photolithographic processes is incompatible with low-cost, high-throughput roll-to-roll processing. Here, we demonstrate solution-deposited oxide thin film transistors (TFTs) on a shape memory polymer substrate, which offers unique control of final device shape and modulus. The key enabling step is the exposure of the precursor film to UV-ozone through a shadow mask to perform patterning and photochemical conversion simultaneously. These TFTs exhibit mobility up to 160 cm2/(V s), subthreshold swing as low as 110 mV/dec, and threshold voltage between −2 and 0 V, while maintaining compatibility with a flexible form factor at processing temperatures below 250 °C.

Dynamic-mode cantilever sensors are used in many different applications but especially in materials research to study properties of novel (nano)materials. Decreasing sample sizes require an increase in sensitivity of the analysis tools. For cantilever-based methods that is achieved through a reduction in cantilever dimensions. However, the increase in sensitivity has to be balanced with the detectability as also for a small cantilever a reliable detection of its oscillatory state has to be ensured. A recently introduced co-resonant measurement principle for cantilever sensors addresses this challenge by coupling and eigenfrequency matching of a micro- and a nanocantilever. Here, the sensor concept is reviewed with focus on the application in materials research by the instructive example of an iron-filled carbon nanotube, giving insight into the features and benefits of the sensor concept and demonstrating the reliable derivation of magnetic sample properties.

Environment can impact the wear behavior of metals and alloys substantially. The tribological properties of Al0.6CoCrFeNi high-entropy alloys (HEAs) were investigated in ambient air, deionized water, simulated acid rain, and simulated seawater conditions at frequencies of 2–5 Hz. The as-cast alloy was composed of simple face-centered cubic and body-centered cubic phases. The wear rate of the as-cast HEA in the ambient air condition was significantly higher than that in the liquid environment. The wear resistance in seawater was superior to that in ambient air, deionized water, and acid rain. Both the friction coefficient and wear rate in seawater were the lowest due to the formation of oxidation film, lubrication, and corrosion action in solution. The dominant wear mechanism in the ambient air condition and deionized water was abrasive wear, delamination wear, and oxidative wear. By contrast, the wear mechanism in acid rain and seawater was mainly corrosion wear, adhesive wear, abrasive wear, and oxidative wear.

Poly(3,4-ethylenedioxythiophene) (PEDOT) is synthesized through a micellar dispersion that allows incorporation of biomolecules into this conductive polymer layer. A PEDOT:κ-carrageenan (κC) system was obtained by electrodeposition and it was compared with a standard PEDOT:sodium dodecyl sulfate electrode coat. The electrochemical behavior and the oxidation level after 1000 cycles were studied through cyclic voltammetry and μRaman spectroscopy. The oxidation ratio in the PEDOT increased while electrochemical activity decreased in both cases. Moreover, the PEDOT:κC system allowed the immobilization of the acetylcholinesterase enzyme, which retained its activity. The unique combination of properties is a key feature in the bioelectronics field.

Single-phase concentrated solid solution alloys (SP-CSAs) are newly emerging advanced structural materials, which are defined as multiprincipal element solid solutions. SP-CSAs with more than four components in equimolar or near-equimolar ratios are also referred to as high-entropy alloys due to their high configurational entropy. SP-CSAs are potential structural materials in advanced nuclear energy systems due to their attractive mechanical properties. Therefore many investigations have been carried out to study the irradiation-induced structural damage and defect behavior in SP-CSAs. This paper reviews recent experimental results on the irradiation responses of various SP-CSAs, focusing on the accumulation of irradiation-induced structural damage, void swelling resistance, and solute segregation behavior. In addition, the characteristic defect behavior in SP-CSAs derived from ab initio and molecular dynamics simulations, as well as the challenges in the applications of SP-CSAs for the nuclear energy systems are briefly discussed.

The micro-nano rough structure promotes the formation of superhydrophobic surfaces, while the formation of superoleophobic surfaces requires the support of re-entrant structures. Electrochemical etching and boiling water treatment methods were used to process the superoleophobic surface in the Al–Mg alloy substrate. The differences between the potential of the aluminum and the magnesium promoted the formation of the surface microstructure under the current stimulation, and the surface was formed into dense nanoscale needle-like coating after boiling water treatment. Scanning electron microscopy, energy dispersive spectroscopy, and contact angle measurement were performed to characterize the morphological features, chemical composition, and surface wettability, respectively. The so-prepared superoleophobic surfaces showed high contact angles and small sliding angles for water, ethylene glycol, and hexadecane. In addition, surface topography, reaction mechanism, and experimental parameters were also studied.

Classical alloy design strategies often aim to benefit from metastability. Examples are numerous: metastable transformation- and twinning-induced plasticity steels, cobalt or titanium based alloys, age hardenable aluminum alloys, and severe plastic deformed nanostructured copper. In each of these cases, superior engineering property combinations are achieved by exploring limits of stability. For the case of high-entropy alloys (HEAs), on the other hand, majority of present research efforts focus on exploring compositions that would yield stable single-phase structures. HEA metastability and its effects on microstructure and property development constitute only a relatively small fraction of ongoing work. To help motivate and guide a corresponding shift in HEA research efforts, here in this paper, we provide an overview of the research activities on metastability in HEAs. To this end, we categorize the past research on the topic into two groups based on their focus, namely, compositional and structural stability, and discuss the most relevant and exciting findings.

Herein, we report the detailed optoelectronic characteristics of low cost fabricated pristine and 1, 5, 10, and 15 wt% Mg-doped ZnO films on the FTO substrate (MZO/FTO) through the spin coating technique. High crystallinity and single phase of the film were confirmed by X-ray diffraction investigation. The average crystallite size was in the range of 46–78 nm. Homogeneous distribution of Mg doping in ZnO was approved by elemental mapping analysis. The fiber-like surface morphology was confirmed by the scanning electron microscopy analysis. Optical transparency was observed in the range of 40–80% for the fabricated films. The optical band gaps for direct and indirect transitions obtained from Tauc’s relation are in the range of 3.103–3.283 eV and 2.423–2.968 eV, respectively. It is also observed that the energy gap of MZO films decreases with an increase in Mg doping from 1 to 15%. The respective stable values of absorption and refractive indices are obtained in the range of ∼0.036–0.088 and ∼1.71–2.1. The linear and nonlinear optical susceptibilities as well as the nonlinear refractive index values were calculated. Additionally, Z-scan measurement was carried out at 532 nm wavelength. The nonlinear absorption coefficient and the imaginary part of third-order nonlinear susceptibility were estimated and corresponding values are obtained in the range of 0.35–123 (×10−5) cm/W and 0.084–29.7 (×10−8) e.s.u., respectively. Moreover, the optical limiting threshold values were obtained in the range of 2.57–6.34 kJ/cm2. The MZO/FTO films are showing strong optical limiting behavior compared to pristine. The output results suggest that MZO films are better contenders for optoelectronic applications.

Given the global water challenges, solar-driven steam generation has become a renewed topic recently as an energy-efficient way for clean water production. Here, a hybrid plasmonic structure consisting of a top layer of TiN nanoparticles (NPs) and a bottom layer of mesoporous anodized alumina membrane (AAM) was rationally designed and fabricated. The top TiN NPs with broadband light absorption acted as a plasmonic heating layer, which converted the absorbed light to heat efficiently for interfacial water heating. The AAM acted as the mechanical support layer, guaranteeing the heat isolation and continuous water replenishment. With optimized thickness of the TiN top layer, a solar steam generation efficiency of 87.7% was achieved in this study. This efficiency is comparable or even higher than prior studies. The current work proves the capability of the TiN NPs as an alternative photothermal material.

Electronic structures of single crystal pentacene are of great interest for the elucidation of charge carrier transport in organic semiconductor materials. Experimental observation of valence band dispersion was recently achieved on single crystal samples of pentacene; however, its intrinsic properties are still unresolved because past experiments were performed on specimens with surface oxides formed by exposure to the ambient atmosphere. In this work, X-ray photoelectron spectroscopy (XPS) and angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) were conducted on single-crystal pentacene samples prepared without ambient exposure. The XPS results confirmed the reduction of the abundance of oxide impurities on the present samples. The ARUPS measurements clearly resolved the valence band structures of the single-crystal pentacene in four symmetry directions of the surface Brillouin zone, indicating anisotropy of at least a factor of 2.4 for the intermolecular transfer integral and hole effective mass at the valence band maximum.

ZnAl–Zr(X) hydrotalcite-like materials were synthesized by co-precipitation using a Zn/Al molar ratio of 2 and Zr/Al(X) molar ratios of 0.0, 0.10, and 0.25. The effect of the activation temperature on the catalytic performance of these materials was analyzed, revealing that at relatively low temperature (200 °C), the collapse of the material structure is diminished, leading to FAME yields varying from 68 to 82%. This remarkable catalytic activity is related to the formation of hydrotalcite, zincite, and hydrozincite which in turn lead to the generation of Brönsted basic sites and Lewis acid–basic pairs. Incorporation of Zr+4 into the brucite-like structure of hydrotalcites enhances the basicity of ZnAl–Zr(X) catalysts, which correlates well with the increase in catalytic activity observed for these catalysts. The stability of the ZnAl–Zr(0.25) catalyst was further studied, showing insignificant deactivation after five subsequent reaction cycles. A simplified reaction scheme was proposed for the transesterification reaction over these materials.

Three-dimensional (3D) printed poly (ethylene glycol) diacrylate (PEGDA) objects have been reinforced with 1%, 3% and 5% silica (SiO2) nanoparticles. Rheological characterizations were conducted for each formulation and 3D-printed using a stereolithographic apparatus (SLA) 3D printer. The tensile and compressive properties of the as-printed nanocomposites were investigated and compared with unreinforced samples. Additionally, the mechanical properties of the objects before and after swelling the samples in deionized water were compared with as-printed ones. Adding SiO2 increased the tensile and compressive strengths of the 3D-printed PEGDA. The tensile and compressive strengths of swollen PEGDA/SiO2 nanocomposite specimens were generally higher than the unswollen specimens.

Single photon sources (SPS) are an important building block for realizing quantum technologies for computing, communication, and sensing. For industrialization, electrically controllable color centers acting as SPS are required. We have demonstrated the creation of electrically controllable silicon vacancies (VSis) in the SiC pn junction diode fabricated by proton beam writing (PBW). PBW was successfully used to introduce electrically controllable VSi without degradation of the diode performance. The dependence of the electroluminescence (EL) and photoluminescence (PL) intensities from VSi on H+ fluence revealed that the emission efficiency of EL is less than that of PL. For EL, the supply of carriers (electrons and/or holes) was restricted due to the resistive region around each VSi introduced by PBW. The results suggest that further improvement in the VSi creation process without defects acting as majority carrier removal centers (highly resistive region) and nonradiative centers by optimization of PBW conditions are key points to realize highly sensitive quantum sensors using VSi.

Hydrogen exposure has been found to result in metal embrittlement. In this work, we use nanoindentation to study the mechanical properties of polycrystalline tungsten subjected to deuterium plasma exposure. For the purpose of comparison, nanoindentation tests on exposed and unexposed reference tungsten were carried out. The results exhibit a decrease in the pop-in load and an increase in hardness on the exposed tungsten sample after deuterium exposure. No significant influence of grain orientation on the pop-in load was observed. After a desorption time of td ≥ 168 h, both the pop-in load and hardness exhibit a recovering trend toward the reference state without deuterium exposure. The decrease of pop-in load is explained using the defactant theory, which suggests that the presence of deuterium facilitates the dislocation nucleation. The increase of hardness is discussed based on two possible mechanisms of the defactant theory and hydrogen pinning of dislocations.