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4H-SiC is one of the most promising indirect wide-bandgap (3.3 eV) semiconductor for power devices used in the emerging area of high-voltage and high-temperature electronics as well as space and radiation harsh environments applications. The wide diffusion of devices in SiC is related to the high quality of the crystals, both for substrates and epitaxial layers. In this work, we performed thermal treatments in Argon atmosphere at temperatures below 2000°C with the aim to study the thermal stability of substrates of 4H-SiC. The wafer substrates were characterized by micro-Raman spectroscopy, Atomic Force Microscopy and Electrostatic Force Microscopy. The thermal treatments induced inhomogeneity of the wafer surface due to a graphitization process starting from 1600°C.

Supplementary Figures S1 & S2 from MET Overexpression Turns Human Primary Osteoblasts into Osteosarcomas

The MET oncogene was causally involved in the pathogenesis of a rare tumor, i.e., the papillary renal cell carcinoma, in which activating mutations, either germline or somatic, were identified. MET activating mutations are rarely found in other human tumors, whereas at higher frequencies, MET is amplified and/or overexpressed in sporadic tumors of specific histotypes, including osteosarcoma. In this work, we provide experimental evidence that overexpression of the MET oncogene causes and sustains the full-blown transformation of osteoblasts. Overexpression of MET, obtained by lentiviral vector–mediated gene transfer, resulted in the conversion of primary human osteoblasts into osteosarcoma cells, displaying the transformed phenotype in vitro and the distinguishing features of human osteosarcomas in vivo. These included atypical nuclei, aberrant mitoses, production of alkaline phosphatase, secretion of osteoid extracellular matrix, and striking neovascularization. Although with a lower tumorigenicity, this phenotype was superimposable to that observed after transfer of the MET gene activated by mutation. Both transformation and tumorigenesis were fully abrogated when MET expression was quenched by short-hairpin RNA or when signaling was impaired by a dominant-negative MET receptor. These data show that MET overexpression is oncogenic and that it is essential for the maintenance of the cancer phenotype. (Cancer Res 2006; 66(9): 4750-7)

Supplementary Figure S3 from MET Overexpression Turns Human Primary Osteoblasts into Osteosarcomas

In this paper, we use numerical simulations to investigate ultrathin Cu (In1-xGax) Se2 solar cells. In the first part, we focus on the cell configuration in which the PV parameters fit and match the fabricated cell characteristics. Our goal is to investigate the impact of different loss mechanisms such as interface trap density (Dit) and absorber trap density (Nt) in different cell pitch sizes on cell performance. Dit defines the amount of carrier’s traps at CIGS/Al2O3 interface to recombine with photogenerated carriers. Nt defines the amount of carrier traps in the absorber layer. It has been found that the recombination via traps is the major loss mechanism in the investigated cell. Further numerical investigations quantify significant improvements in cell performance for different cell pitch sizes, absorber doping densities, Ga content, and graded bandgap at a fixed opening width in the Al2O3 layer. Consequently, for tandem configuration, the optimized single u-CIGS cell has been used as a top cell with a PERT silicon cell which aroused this recent decade as a promising strategy to achieve maximum efficiencies. The results from these simulations provide insights for ultrathin film CIGS solar cell optimization.

We use Silvaco-TCAD tools to optimize ultrathin Cu (In1-xGax) Se2 solar cells with rear surface passivation. First of all, the single CIGS structure was performed and calibrated with the electrical and optical output of the experimental results. Based on the simulation and example results, considering the variety of carrier’s transport mechanism at the heterointerface CdS/CIGS shows a significant impact on cell performance. The proposed rear passivated ultrathin CIGS structure consists the following configuration: MgF2 (120 nm)/ZnO:Al (300 nm)/ZnO(100 nm)/CdS(50 nm)/CIGS(500 nm)/Al2O3/Ag/glass-substrate. The effect of the rear-passivated, absorber thickness (CIGS), and cell pitch on ultrathin CIGS cell performance is analyzed and studied under AM 1.5G, 1 sun illumination. This increases the model’s total implied photocurrent density from 21.1 to 29.1 mA/cm2. The simulations show that the ultrathin CIGS cell efficiencies of up to 13% can be obtained. The results from these simulations are compared with the measured characteristics of the fabricated cell.

The FinFET architecture has attracted growing attention over the last two decades since its invention, owing to the good control of the gate electrode over the conductive channel leading to a high immunity from short-channel effects (SCEs). In order to contribute to the advancement of this rapidly expanding technology, a 3D 14-nm SOI n-FinFET is performed and calibrated to the experimental data from IBM by using Silvaco TCAD tools. The calibrated TCAD model is then investigated to analyze the impact of changing the fin width, fin height, gate dielectric material, and gate length on the DC and RF parameters. The achieved results allow gaining a better understanding and a deeper insight into the effects of varying the physical dimensions and materials on the device performance, thereby enabling the fabrication of a device tailored to the given constraints and requirements. After analyzing the optimal values from different changes, a new device configuration is proposed, which shows a good improvement in electrical characteristics.

Surface plasmons (SP) arising from nanometer silicon objects allow control and manipulation of light at the nanoscale exhibiting significant advantages in a plethora of applied research areas such as nanophotonic, environment, energy, biology, and medicine. These SP can achieve more significant potential, thanks to the industrial scalability and low cost offered by silicon compared with other metals and semiconductor nanosized materials. However, as they have not yet been fully understood and exploited, silicon’s plasmon mechanisms need to be thoroughly studied. In particular, the influence of nanowire shape on surface plasmon behavior and the existence of physical constraints for surface plasmon excitation remains to be fully understood. In a previous study, we have demonstrated that thanks to their anisotropic one-dimensional shape, silicon nanowires sustain two types of plasmon resonances, the longitudinal ones along the main nanowire axis, with harmonic behavior and the transversal resonance, which takes place along the diameter. We demonstrated our data on a particular set of sizes, 30 nm for the diameter and about 400 nm for the length. Here we show how the resonances change when the diameter is smaller than 30 nm and the length is smaller than 400 nm. We use electron energy loss spectroscopy to map the several plasmonic modes from the fundamental one to the higher orders, with the goal of understanding how the SP resonances change when the diameter and length are smaller than 30 nm and 400 nm, respectively. We then use modeling to support the experimental findings. According to the mode order, the study illustrates the various locations inside the nanowires where discrete resonance spots can be found. Another important finding of this work is the disappearance of the surface plasmon modes for nanowires shorter than a predetermined threshold for any diameter in the range investigated, showing that the nanowire length is a key factor in maintaining electron oscillations. With this finding, a crucial physical limit for this phenomenon in silicon is established.

Superhydrophobic surfaces on 6082 aluminum alloy substrates are tailored by low-cost chemical surface treatments coupled to a fluorine-free alkyl-silane coating deposition. In particular, three different surface treatments are investigated: boiling water, HF/HCl, and HNO3/HCl etching. The results show that the micro-nano structure and the wetting behavior are greatly influenced by the applied surface texturing treatment. After silanization, all the textured surfaces exhibit a superhydrophobic behavior. The highest water contact angle (WCA, ≈180°) is obtained by HF/HCl etching. Interestingly, the water sliding angle (WSA) is affected by the anisotropic surface characteristics. Indeed, for the HF/HCl and the HNO3/HCl samples, the WSA in the longitudinal direction is lower than the transversal one, which slightly affects the self-cleaning capacity. The results point out that the superhydrophobic behavior of the aluminum alloys surface can be easily tailored by performing a two-step procedure: (i) roughening treatment and (ii) surface chemical silanization. Considering these promising results, the aim of further studies will be to improve the knowledge and optimize the process parameters in order to tailor a superhydrophobic surface with an effective performance in terms of stability and durability.

Severe acute respiratory syndrome (SARS)-CoV-2 virus disease (coronavirus disease 2019; COVID-19) is associated with increased coagulation activity, resulting in an excessive risk of venous thromboembolism (VTE) and poor prognosis. The most common manifestation of VTE is pulmonary embolism (PE), with approximately one in five hospitalised patients being at risk. These reports led to the empirical use of prophylactic anticoagulation, even in the absence of established or clinically suspected disease. This review summarises current aspects and recommendations regarding the use of thromboprophylaxis for PE in patients with COVID-19.

Transition metal oxides on reduced graphene oxide (TMO@rGO) nanocomposites were successfully prepared via a very simple one-step solvothermal process, involving the simultaneous (thermal) reduction of graphene oxide to graphene and the deposition of TMO nanoparticles over its surface. Texture and morphology, microstructure, and chemical and surface compositions of the nanocomposites were investigated via scanning electron microscopy, X-ray diffraction, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy, respectively. The results prove that Fe2O3@rGO, CoFe2O4@rGO, and CoO@rGO are obtained by using Fe and/or Co acetates as oxide precursors, with the TMO nanoparticles uniformly anchored onto the surface of graphene sheets. The electrochemical performance of the most promising nanocomposite was evaluated as anode material for sodium ion batteries. The preliminary results of galvanostatic cycling prove that Fe2O3@rGO nanocomposite exhibits better rate capability and stability than both bare Fe2O3 and Fe2O3+rGO physical mixture.

A novel bis-pillar[5]arene dicarboxylic acid self-assembles in the presence of 1,12-diaminododecane to yield overall neutral, internally ion-paired supramolecular polymers. Their aggregation, binding mode, and morphology can be tuned by external stimuli such as solvent polarity, concentration, and base treatment.

Power SiC MOSFETs are going to substitute Si devices by to their significantly better performances that make them much suitable in power switching applications such as electric/hybrid vehicles. The increasingly use of these devices in critical mission profiles requires an ever-higher reliability, whereas the increase of the dissipated power during high-speed working cycling due to short current pulses leads to unavoidable thermal and mechanical stress. Here, we propose a direct method to evaluate the mechanical stress due to current pulses. This method highlights that high Power SiC-based MOSFET undergoes to almost two different thermomechanical processes with completely different time scale. The results allow a link between the thermo-mechanical stress and the device failure conditions, with special focus on the current pulses effects on metal surface, as this is a main power devices weakness.

In recent years, power electronics has played a fundamental role in the development of increasingly efficient circuits for energy conversion. The characterization of a Power MOSFET under a gate overstress and the correlation with the reliability performances represent a crucial point in the optimization of the trench technology where the oxidation processes of the gate oxide are critical in terms of uniformity and reproducibility of the thickness. This article explores these aspects with particular attention to the analysis of the electrical overstress effect on aging transistors parameters and the classical TDDB (time dependent dielectric breakdown) test for gate oxide integrity characterization and lifetime extrapolation. The latter actually trigger oxide breakdown which is not as relevant at operating conditions as parametric degradation which usually occurs much earlier. Moreover, a possible physical explanation to the adherence of both failure modes (breakdown and transistor aging) to the two typical failure model such as thermochemical model and anode hole injection has been subjected to analysis following fitting methods as did in the past including their reciprocal correlation.

Different concentrations (0.1, 0.2, 0.5, and 1 wt%) of OH-functionalized carbon nanotubes (CNTs) were used to prepare high-density polyethylene (HDPE) based composites via melt blending in the presence of a maleinized polyethylene (PE-g-MA) as a coupling agent. The mechanical behaviour of the produced HDPE/CNT composites was investigated in view of their possible application as reinforced materials in the civil structures and understood in terms of the structural modifications produced by the incorporation of CNTs in the HDPE matrix. The dispersion of CNTs in the polymer matrix, a key parameter to the ends of the mechanical performance of the composites, was evaluated at different observation scales, from few micrometers to some millimeters, by means of transmission electron microscopy (TEM), micro-Raman spectroscopy (MRS) and acoustic image analysis. The comparative discussion of the results obtained allowed clarifying the reason for the lack of a net improvement in the mechanical behaviour of the composites with respect to the pristine polymer.

Crystalline hematite/polycrystalline nickel oxide (α-Fe2O3/NiO) core/shell nanofibers are prepared by electrospinning and calcination, followed by a varying number (100–1150) of atomic layer deposition cycles of NiO. The deposition of the conformal NiO layer leads to the passivation of the surface states and the appearance of a photoluminescence band in the micro-Raman spectra excited by 532 nm laser. As a continuous NiO layer is formed, a peak, possibly arising from a two-magnon mode, appears at 1585 cm−1. The detection of the peak, which is not observed in the spectra excited by a 633 nm laser, is assisted by the surface plasmon at around 510 nm introduced by the polycrystalline NiO layer, due to the electron doping induced by coordination-defects at its edge-rich surface.

Due to their outstanding physicochemical properties, the next generation of the graphene family&mdash, graphene quantum dots (GQDs)&mdash, are at the cutting edge of nanotechnology development. GQDs generally possess many hydrophilic functionalities which allow their dispersibility in water but, on the other hand, could interfere with reactions that are mainly performed in organic solvents, as for cycloaddition reactions. We investigated the 1,3-dipolar cycloaddition (1,3-DCA) reactions of the C-ethoxycarbonyl N-methyl nitrone 1a and the newly synthesized C-diethoxyphosphorylpropilidene N-benzyl nitrone 1b with the surface of GQDs, affording the isoxazolidine cycloadducts isox-GQDs 2a and isox-GQDs 2b. Reactions were performed in mild and eco-friendly conditions, through the use of a natural deep eutectic solvent (NADES), free of chloride or any metal ions in its composition, and formed by the zwitterionic trimethylglycine as the -bond acceptor, and glycolic acid as the hydrogen-bond donor. The results reported in this study have for the first time proved the possibility of performing cycloaddition reactions directly to the p-cloud of the GQDs surface. The use of DES for the cycloaddition reactions on GQDs, other than to improve the solubility of reactants, has been shown to bring additional advantages because of the great affinity of these green solvents with aromatic systems.

The effect of surface microstructure on erosion-corrosion resistance of hydrophobic rough and smooth nickel electrodeposited coatings was investigated using on site electrochemical impedance spectroscopy in dynamic solution of 3.5 wt.% NaCl + 40 wt.% sand. Atomic force microscopy (AFM) was used to track damage initiation at the surface of the coatings during erosion-corrosion. Changes in the hydrophobic behavior of the coatings during erosion-corrosion were recorded. It was observed that the rough nickel coating was not erosion resistant and about 65% of its initial average roughness was lost after 30 min of erosion-corrosion. This loss of roughness approached to about 80% after 1 h of erosion-corrosion. The water contact angle of the rough nickel coating after two weeks of storing in the air was about 131° which decreased to about 115° after 30 min of erosion-corrosion and to about 78° after 1 h of erosion-corrosion. However, during erosion-corrosion tests, the polarization resistance of the rough nickel coating was constantly higher than that of the smooth nickel coating notwithstanding the significant loss of its surface microstructural features.

This paper deals with an accurate experimental investigation of the optical sensing behavior of a microwave low-noise amplifier (LNA). The tested amplifier, employing a commercial InGaAs pHEMT has been analyzed in terms of the scattering parameters and the noise figure. The analysis has been carried out by observing how the device behavior is influenced by a continuous wave laser illumination for different optical wavelengths, power levels, and bias conditions. It has been assessed that the LNA performance is significantly influenced by the light exposure with optical effects more pronounced at higher wavelengths for a fixed incident power. Upon applying the recommended bias conditions of the sensing amplifier, the main changes consist of a degradation of the noise figure and gain. As opposite to this, an overall performance enhancement is clearly recognizable with the amplifier biased at the transistor pinch-off. The results obtained in the present work fully confirm a theoretical analysis previously carried out by employing different devices and LNA design.

This paper presents the results of an investigation of Passivated Emitter Rear Cell (PERC) solar cell technology and the current understanding of the fundamental device physics. The research work has been focused on the influence of the bulk lifetime, the incident angle of the solar radiation, and temperature dependence on electrical properties of the considered PERC solar cell by using TCAD-ATLAS Silvaco. Also, this paper shows the best results obtained recently and some guidelines to improve still more the efficiency of the devices. The optimization at 300 K led to the following results Jsc = 41.70 mA/cm2, Voc = 0.727 V, FF = 80.53 %, P $_{{\max }} =$ 244.439 W/m− 2, and η = 24.44 % which are close with those found in different research works. This technology provides a better electrical control over the cell and thus leads to valuable improvements in device performance.

This paper investigates recent developments in Interdigitated Back Contact (IBC) solar cell physics and technology by using ATLAS Silvaco device simulator. The work has been focused on improvement of structural and electrical properties by using zinc oxide layer to passivate the front surface of a crystalline silicon (c-Si) substrate. In a silicon cells, the device performance crucially depends on the quality of the n-ZnO/c-Si heterojunction. Simulation results for various front dielectric material, emitter doping concentration, and semiconductor material for the front surface field (FSF) layer on the considered structure are reported and analyzed. These variations have a direct impact on the electrical device characteristics. We could determine the critical parameters of the cell and optimize its main parameters to obtain the highest performance for IBC solar cell. Therefore, we present our best results obtained recently and some guidelines to improve still more the efficiency of the devices. The optimization at 300 K led to the following results Jsc = 41.89 mA/cm2, Voc = 0.727 V, FF = 85.23 %, P $_{\max }=$ 259.95 W/m-2, and η =25.99 % which are close with those found in different works. The structure simulation will simplify the manufacturing processes of solar cells; will thus reduce the costs while producing high outputs of photovoltaic conversion. Finally, we finish by a summary of the main advantages of this technology taking into account all the parameters described above.

Pure and titanium- or silicon-doped iron oxide fibres are synthesised by electro-spinning over conductive fluorine doped tin oxide (FTO)/glass substrates, and the effect of the type of dopant on the morphology of the fibres and the crystalline phase of the oxide is investigated by means of several complementary characterisation techniques. Results show that in the absence of dopant, highly porous fibres, consisting of interconnected polycrystalline hematite grains, are obtained. Doping with titanium does not influence the crystalline phase of the oxide, but the better packed structure of the fibres causes them to detach from the support. Silicon-doping results in a different phase of the host oxide (maghemite) and good adhesion of the fibres to the FTO/glass support. Very preliminary tests to evaluate the photo-electrochemical activity of the samples demonstrate that the photocurrent measured with Si-doped maghemite fibres is 53% higher with respect to that obtained with pure hematite fibres, as an effect of the nearly threefold increase in the donor concentration brought about by doping. This, in turn, improves the charge transfer at the interface, leading to a higher charge injection from the electrode to the electrolyte and, thus, to a greater photo-oxidation efficiency.

Pure and Al- and/or Ca-added ZnO fibers are synthesized by electro-spinning. Their morphological, structural and optical properties are investigated by means of several complementary characterization techniques, focusing attention on optical properties and fiber surface roughness, which are of relevance in many applications. The comparative analysis of the results obtained demonstrates that all the fibers consist of rounded polycrystalline oxide nanoparticles interconnected to each other, with the (dopant-dependent) nanoparticle size controlling their surface roughness. Non-stoichiometry affects all the samples and strongly influences their photoluminescence properties. Calcium segregates in a secondary phase forming calcite. On the contrary, aluminum well disperses within zincite as an isolated impurity, with Al 3+ ions substituting Zn 2+ ions in the ZnO lattice. Its content controls the relative exciton-to-defect emission band intensity, as well as the frequency of the main Zn O absorption peak.

I read the paper by Liang et al. ([1][1]) with great interest and congratulate the authors on their excellent work. As the authors correctly state, elevated long-term fine particulate matter (PM2.5) exposures lead to increased cardiovascular disease (CVD) risk in China. The effects are more