Doping is a potent and often used strategy to modify properties of active electrode materials in advanced electrochemical batteries. There are several factors by which doping changes properties critically affecting battery performance, most notably the voltage, capacity, rate capability, and stability. These factors have to do specifically with changes in structure, band gap and band structure, and structural instability induced by doping. We review our recent modeling works on the effects of doping of active electrode materials, notably for prospective materials for organic and post-lithium (Na ion, Mg ion) batteries, as well as present new results, to build a coherent view on the use of n- and p-doping to modulate Li, Na, and Mg storage properties, most notably voltage. Specifically, we clearly point out effects due to electronic structure and those due to strain (structural instability), which clears some confusion about the effects of n- versus p-doping and facilitates rational rather than ad hoc design of doped materials.

The tunnel field-effect transistor (TFET) is one of the candidates replacing conventional metal–oxide–semiconductor field-effect transistors to realize low-power-consumption large-scale integration (LSI). The most significant issue in the practical application of TFETs concerns their low tunneling current. Si is an indirect-gap material having a low band-to-band tunneling probability and is not favored for the channel. However, a new technology to enhance tunneling current in Si-TFETs utilizing the isoelectronic trap (IET) technology was recently proposed. IET technology provides a new approach to realize low-power-consumption LSIs with TFETs. The present paper reviews the state-of-the-art research and future prospects of Si-TFETs with IET technology.

We demonstrate the tungsten disulfide (WS2) thin film catalysts prepared by the sulfurization of vacuum deposited WO3 thin films for efficient hydrogen production with over 90% Faradaic efficiency. The 23-nm-thick WS2 thin film catalyst heterojunction with p-type silicon photocathode could exhibit a photocurrent density of 8.3 mA/cm2 at 0 V versus a reversible hydrogen electrode (RHE), a low onset potential of 0.2 V versus RHE when photocurrent density reaches −1 mA/cm2 and long-term stability over 10 h. The enhanced catalytic activities of WS2/p-Si photocathodes compared with the bare p-Si photocathode originate from a number of edge sites in the synthesized polycrystalline thin films, which could act as hydrogen evolution catalyst.

An aqueous suspension of 5 vol% silicon (Si) nanoparticles was directionally solidified at substrate temperatures between −10 and −25 °C, resulting in colonies of aligned pure ice dendrites separated by interdendritic Si particles packed walls. Channels are created by sublimation of the dendrites, and the surrounding Si walls are densified by sintering. The resulting Si foams exhibit a 76 ± 2% macroporosity, with the width of the ice-templated channels and the Si walls decreasing with solidification temperature, from 106 to 60 µm and from 34 to 17 µm, respectively. Si walls show high surface roughness from inverse templating of short secondary ice dendrite arms.

Polyphenylene sulfide (PPS) has good corrosion resistance, chemical stability, and thermal stability, which was widely applied in precipitator field. In this paper, a novel in situ synthesis protocol was selected to fabricate the Mn–CeO x /PPS functional composites with excellent low-temperature denitration activity. Results show that the as-obtained Mn–CeO x /PPS filter possessed of superb denitration activity at 180 °C under a weight hourly space velocity of 210,000 mL/gcat/h, which may be stemmed from the generation of amorphous and well-dispersed mixed metal oxide catalysts.

The great properties of the paramagnetic nitrogen-vacancy (NV) color center in diamond predestine it for nanoscale sensor applications; however, these properties are often compromised when NV centers reside near diamond surface for sensing. Here we show in a mini review that first-principles calculations can characterize diamond surfaces and predict the ideal surface terminators to host NV sensors. We discuss technical issues on the modeling of NV centers close to diamond surfaces, and results on the most employed diamond (100) and the most promising (111) surfaces with various terminators involving hydrogen, oxygen, fluorine, and nitrogen are presented.

SiN x films were grown by plasma-enhanced chemical vapor deposition on Si substrates with the composition controlled by the flow ratio R: ammonia to silane in the range R = 0.45–1.0. Then SiN x films were annealed at 1100 °C for 30 min to form Si-quantum dots (QDs). Fourier transform infrared spectroscopy study permits estimating SiN x compositions. Photoluminescence (PL) spectra of SiN x films included bands peaked at: 2.87–2.99, 2.42–2.54, 2.10–2.25, and 1.47–1.90 eV. Former three PL bands are attributed to emission via defects in SiN x films. Fourth PL band is assigned to exciton emission in Si QDs, detected by transmission electron microscopy study in films grown at R ≤ 0.67. The nature of non-radiative defects in SiN x films is discussed as well.

Harnessing the properties of imidazolium species, antimicrobial activity against Gram-negative and Gram-positive bacteria was attained by binary-grafting 2-hydroxyethyl methacrylate (HEMA) or N-isopropylacrylamide, followed by N-vinylimidazole onto polypropylene (PP) monofilaments (sutures) using 60Co γ-rays. Ulterior functionalization with methyl iodide was carried out to endow brushes with antimicrobial activity on the PP surface. The PP-grafted sutures were characterized by means of Fourier-transform infrared spectroscopy attenuated total reflection, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis, and regarding the mechanical properties and the responsiveness to pH and temperature. Tests were performed on Escherichia coli and Staphylococcus aureus achieving large inhibition zones.

A non-precious metal catalytic system of Fe-doped Ta2O5 is developed by pulsed laser deposition toward efficient oxygen evolution reaction (OER). The optimal Fe concentration is determined to be 5 at.% for optimized OER activity via a series of electrochemical characterizations. The 5 at.% Fe-doped Ta2O5 nanolayer possesses a low onset overpotential of 0.22 V, an overpotential of 0.38 V at 10 mA/cm2 and a Tafel slope of 54 mV/dec. Comprehensive first-principles calculations attribute the enhanced OER activity to the substitutional FeTa dopants, which generate a new active OER site on surface and simultaneously accelerate electron transfer over oxygens.

Here we report a doping method based on charge transfer interaction for an easily obtainable carbon material, carbon black (acetylene carbon black and Ketjenblack), as a main raw material. The n-type doping of those carbon blacks, generally p-type material, was conducted with a molecular dopant, triphenylphosphine (tpp). The key was to modify the surface of carbon blacks with silver (Ag) nanoparticles to attach tpp molecules on the surface of Ag. Our method is expected to be used for the fabrication of functional devices (such as thermoelectric devices) from p- and n-type materials.

Ni–Pt polyhedral nanoparticles were synthesized through a thermochemical route by the hot-injection method using Oleylamine (Oam) and Oleic acid (Oac) solvents as simultaneous stabilizing and reducing agents. Several syntheses were performed to study the effect of the hot-injection temperature on nanoparticle size distribution. Results revealed that the injection of precursors in a mixture of Oam and Oac at 180 °C produced paramagnetic nanoparticles with an approximate size of 27 nm; these particles have uniformly defined polyhedral structures and show greater Pt accumulation on the edges and corners. Ni–Pt polyhedral nanoparticles with larger sizes and high polydispersity were obtained as the injection temperature was increased closer to the reduction temperature.

Nickel thin films were prepared by electroless plating in a foam of electrolyte that was generated by bubbling nitrogen gas into a hypophosphite-based electroless plating solution to which was added a surfactant of sulfuric acid monododecyl ester sodium salt. Although the film growth rate in the foam was considerably lower than that in the conventional liquid, film growth was enhanced by inducing a flow in the foam. Compared with films deposited in liquid, the films deposited in foam had a smaller number of pinholes, smaller crystallite size, and superior corrosion resistance. The ferroxyl indicator test showed that the area of corrosion can be reduced to less than 1/20 by depositing the film in foam instead of liquid.

Here we report on the material chemistry following crystallization in the presence of water vapor of chlorinated formamidinium lead-triiodide (NH2CH = NH2PbI3−xClx) perovskite films. We found in-situ exposure to water vapor reduces, or possibly eliminates, the retention of chlorine (Cl) inside NH2CH = NH2PbI3−xClx crystals. There is a strong tendency toward Cl volatility, which indicates the sensitivity of these materials for their integration into solar cells. The requisite for additional efforts focused on the mitigation of water vapor is reported. Based on the in situ results, hot casting (<100 °C) in dry conditions demonstrates improved film coverage and Cl retention with efficiencies reaching 12.07%.

Multiwall carbon nanotubes (MWCNTs) are utilized to resolve low coupling coefficient issue by dispersing MWCNTs in poly(vinylidene fluoride) matrix to create stress reinforcing network, dispersant, and electron conducting functions for barium titanate (BT) nanoparticles. Various BT and MWCNT percentages of nanocomposite film are fabricated by FDM three-dimensional (3D) printing which can simplify the fabrication process as well as lower cost and design flexibility. Increasing MWCNTs and BT particles gradually increase piezoelectric coefficient (d 31) by 0.13 pC/N with 0.4 wt%-MWCNTs/18 wt%-BT. These results provide not only a technique to print piezoelectric nanocomposites but also unique materials combination for sensor application.

In this paper, a simple evolution equation for dislocation densities moving on a slip plane is proven. This equation gives the time evolution of dislocation density at a general field point on the slip plane, due to the approach of new dislocations and tilting of dislocations already at the field point. This equation is fully consistent with Acharya's evolution equation and Hochrainer et al.’s “continuous dislocation dynamics” (CDD) theory. However, it is shown that the variable of dislocation curvature in CDD is unnecessary if one considers one-dimensional flux divergence along the dislocation velocity direction.

Pendent-type polymers are attractive materials which allow the flexibility to introduce various redox active moieties that facilitate rapid ion/electron transport and enable charge storage. Here, we demonstrate naphthalene diimide polymers with polynorbornene backbone having N-phenyl, PNAn 5 and N-(4-nitrophenyl), PNNO 6. Small changes in the molecular design have led to a significant difference in bulk material and device properties. PNNO 6 maintained 80% of its capacity at 1C after 10 cycles in a Li-ion coin cell. PNAn 5 displayed exceptionally high charge capacity and rate capability with excellent cyclability, maintaining almost its theoretical capacity at various C-rates throughout 500 cycles.

NV centers in silicon carbide have been identified in the three main polytypes 3C, 4H, 6H by magnetic resonance and photoluminescence experiments and related ab initio calculations. Their properties show them to be promising centers for applications in quantum technology, similar to the case of NV in diamond. However, their spectral range is in the near-infrared, which should allow their integration in telecommunication systems.