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Pt/Co/Hf multilayers were prepared by magnetron sputtering, and the magnetic anisotropy was effectively regulated by Hf thickness and heat treatment in Pt/Co/Hf films. The interface microstructures were characterized. The influence of the interface microstructure on magnetic properties was studied. The results show that the magnetic anisotropy in Pt/Co/Hf films is closely related to the interface microstructure, which is influenced by Hf thickness and the heat treatment temperature. Microstructure analysis shows that after the Pt(3)/Co(1.5)/Hf(1) film is heat-treated, the CoOx content increases, more CoPt(111) forms, the interface is smoother and sharper, and the roughness of the Co/Hf interface decreases. Several factors work together to cause the magnetic anisotropy of the sample to change from in-plane magnetic anisotropy (IMA)to perpendicular magnetic anisotropy (PMA).

Herein, a method is described for pyrolysis associated with in situ ultrasonic synthesis of flower-like p-n-type BiOCl/g-C3N4 assembled with nanosheets for enhancing the visible-light degradation of Rhodamine B (RhB). The formation process, structure, microscopic morphology, and photocatalytic activity of the samples were investigated in detail. In addition, the results of simulated visible light-driven photocatalytic experiments showed that, compared with pure g-C3N4, the BiOCl (20 wt %)/g-C3N4 composite photocatalyst exhibited better degradation ability with a maximum k value of 0.109 min−1, and the most significant total removal rate of RhB was up to 99 %, which is about ninefold in comparison with pure g-C3N4. Finally, the enhanced photocatalytic activities of the products could be attributed to the suitable band structures between the BiOCl/g-C3N4 composite with rich oxygen vacancies for the effective separation of photogenerated electron–hole pairs.

Sodium alginate (SA), as the eco-friendly and human-safe biomass material not only can achieve effective dispersion of graphene nanoplatelets (GnPs), but also improve the interaction between GnPs and cellulose macromolecules. Based on this, a flexible and wearable GnPs/cellulose strain sensor with a special 2 × 2 double rib knitted fabric structure (KFGS) was prepared by a simple dip-coating method that could be used on a large scale. The KFGS exhibited dual sensing performance with high sensitivity (25.32 kPa−1 at 3 kPa pressure, gauge factor 32.62 at 25% tensile strain), stretchability (e > 25%) and dynamic stability (signal drift

The matching of charge transport layer and photoactive layer is critical in solar energy conversion devices, especially for planar perovskite solar cells based on the SnO2 electron-transfer layer (ETL) owing to its unmatched photogenerated electron and hole extraction rates. Graphdiyne (GDY) with multi-roles has been incorporated to maximize the matching between SnO2 and perovskite regarding electron extraction rate optimization and interface engineering towards both perovskite crystallization process and subsequent photovoltaic service duration. The GDY doped SnO2 layer has fourfold improved electron mobility due to freshly formed C-O σ bond and more facilitated band alignment. The enhanced hydrophobicity inhibits heterogeneous perovskite nucleation, contributing to a high-quality film with diminished grain boundaries and lower defect density. Also, the interfacial passivation of Pb-I anti-site defects has been demonstrated via GDY introduction.

The mis-oriented abnormal grains embedded in the sputtered scandium aluminum nitride (ScAlN) film degrade the film piezoelectric response. In this paper, we present for the first time the in-plane TEM observation of the crystal grains morphology and the microstructure of the sputtered Sc 0.2 Al 0.8 N film. The columnar normal grains are highly (0002) textured and exhibit the hexagonal cross-section morphology with six well-developed {1011} side facets. The abnormal grains show irregular cross-section. The grain boundary study reveals that the abnormal grains grow laterally and consume their neighboring normal grains during the film sputtering.

The development of a sensitive flexible wearable temperature sensor has extraordinary significance in the field of human vital signs detection. Herein, we demonstrate a flexible temperature sensor (FTS) fitting on human skin based on non-woven fabric, and it has been systematically characterized and tested for performance. The resistor-type FTS integrated sodium alginate with graphene, behaved as negative temperature coefficient feature and exhibited excellent sensing performance of good sensitivity (TCR = − 1.5 °C−1), high accuracy of 0.1 °C, short response time (26.3 s), high stability and repeatability at the temperature range of 20.0–45.0 °C. Specially, the FTS eliminated strain and humidity interference, so that can be attached to the human body to detect skin temperature changes continuously and stably.

Corrosion and fouling problems, which exist in many industrial processes, severely impede industrial production. Hence, solving these problems is necessary and meaningful. In this work, various fluorinated polysiloxane coatings with hydrophobic characteristics were fabricated and coated on phosphatized Q235 carbon steel (PCS) to improve the corrosion resistance and antifouling performances. The phosphatization of carbon steel was to immerse the sample into phosphating solution for a certain time at 30 oC. The fluorinated polysiloxane coating was fabricated via curing fluorinated polysiloxane sol coated on sample. After corrosion and fouling tests, the better performances of corrosion resistance reflected by higher electrochemical impedance and antifouling presented by less fouling adhesion for coated sample were displayed. Moreover, microscopic morphologies, chemical components, thermal stabilities, surface energies, roughness and adhesiveness of fluorinated polysiloxane coatings were also investigated. The fluorinated polysiloxane coating shows good microscopic uniformity, thermal stability with only 6.1% weight loss at 375 °C and adhesion on substrate.

The control of the interfacial oxidization between metal and oxide by oxygen migration is highly effective in tailoring the interfacial microstructure and consequently their physical, chemical and magnetic properties in the magnetic films. Here, we study the effect of a Mo-spacer on the Ta/MgO/CoFeB/Mo/CoFeB/MgO/Ta films to ensure their perpendicular magnetic anisotropy (PMA) for the film after annealing at 500 °C. High-resolution transmission electron microscopy (HRTEM) shows that the MgO layers are mainly uncrystallized and energy dispersive X-ray spectroscopy (EDS) shows there is a significant diffusion of the small amount of Mo elements. The X-ray photoelectron spectroscopy (XPS) indicates that some MgO compounds are reduced to metallic Mg after annealing. More Fe and Co oxides are formed as oxygen reduced from MgO combines with Fe and Co in the CoFeB layer, which strengthens the PMA. The control of oxygen migration is therefore demonstrated as an effective way to improve magnetic properties.

The effects of Nb buffer layers on the magnetic properties of Nb/CoFeB/MgO/Ta films have been studied. The films exhibited perpendicular magnetic anisotropy (PMA) when the Nb buffer layer thickness approached or exceeded 3 nm. PMA was retained at annealing temperatures up to 350 °C for the films containing 5-nm Nb buffer layer. The Ta, CoFeB, MgO, and Nb layers were easily distinguished by energy-dispersive X-ray spectroscopy. High-resolution transmission electron microscopy showed that the Nb, MgO, CoFeB, and Ta layers were crystalline. X-ray photoelectron spectroscopy indicated that the oxygen reduced from MgO combined with Fe and Co to form FeOx and CoOx after annealing, strengthening the PMA. The Nb(5)/CoFeB(1)/MgO(2)/Ta(3) film exhibited a smooth CoFeB/MgO interface after annealing, as confirmed by X-ray reflectivity. The crystallized MgO and CoFeB, formation of Fe and Co oxides, and smooth CoFeB/MgO interface all contributed to the strong PMA.

In Magnetic tunnel junctions, which are applied in spintronic devices, the key issue is low thermal stability. Here, we study the influence of a W spacer on the perpendicular magnetic anisotropy (PMA) at temperatures up to 525 °C in perpendicular magnetized MgO/CoFeB/MgO structures with thin W spacer. High-resolution transmission electron microscopy (HRTEM) analysis shows that the MgO layers are partially crystallized and a significant diffusion of the small number of W elements is detected. The X-ray photoelectron spectroscopy (XPS) indicates that some WOx compounds were reduced to metallic W and part of MgO were reduced to Mg during annealing. The oxygen released by WOx and MgO combined with Fe and Co, thereby more Fe and Co oxides were formed and thus benefiting the perpendicular magnetic anisotropy (PMA).

We investigated the effect that Ta spacer had on the interfacial microstructures and magnetic properties of MgO/CoFeB/Ta/CoFeB/MgO films. We found that when the Ta spacer thickness was optimized, the double MgO interface led to an enhancement in the perpendicular magnetic anisotropy (PMA) and thermostability. By systematically studying the changes for different structures in the chemical state, we interpreted how elements diffuse and alter the chemical states and properties of the magnetic tunnel junctions (MTJs). We found that increasing the Fe oxide is crucial to the PMA in the films and we attribute the increase in the of Fe oxide content to the oxygen liberated by the reduction of boron oxide.

In this work, a facile method combined with catalyst solution (mixture of AgNO3, 3-aminopropyltriethoxysilane, alcohol, SiO2 particle and deionized water) printing and electroless deposition to fabricate selective copper coating is demonstrated. The catalyst solution can write onto (polyethylene terephthalate (PET)) surface directly with good stability and resolution. The structure can catalyze plating reaction. SiO2 particle can enhance surface roughness (Sr) of catalyst coating. Effects of Sr on electronic, adhesive force and structural properties of copper coating are investigated. High Sr can facilitate the enhancement of Ag-adsorbed amount, deposition rate, adhesive force, crystallinity and electrical stability of plated coating. When the Sr is 0.78 µm, the thickness of copper coating is 2.5 µm, minimum width of copper line is 250 µm, the resistivity is 2.1 × 10−6 Ω cm, adhesion of 2.5 µm thick coating is 5B.

The piezoelectric response of the sputtered scandium aluminum nitride (ScAlN) film are highly dependent on its crystallinity. The film texture continues to develop during the post-annealing process at high temperatures. In this work, the annealing experiments at temperatures up to 1000 °C were conducted on the sputtered ScAlN/Mo film stacks. Temperature dependences of the crystal structure and the stress were evaluated and discussed. The interface between the ScAlN film and the bottom Mo electrode is also inspected to assess the thermal stability. Our results would contribute to the robust piezoelectric device development.

Abnormally oriented grains (AOGs) widely exist in the Sc doped AlN films, especially for Sc concentration more than 15%. In this work, the impact of the AOGs on the performance of ScAlN-based laterally coupled alternating thickness (LCAT) mode resonators and Lamb wave mode resonators are systematically evaluated by FEM modelling. The correlation between the coupling coefficient of the resonators and the parameters of the AOGs, including density, dimension and crystal orientation, is revealed. The simulations are consistent with the on-wafer device measurement results. This study provides a practical method to estimate the effects of the AOGs and a guideline for the ScAlN film optimization for resonators utilizing the lateral modes.

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In this paper, we investigated retention failure behavior in analog RRAM devices. The retention failure time was found to be longer in TiW/ Al 2 O 3 /Ta 2 O 5 /Ta device than that of TiW/HfO 2 /Ta 2 O 5 /Ta device. Higher diffusion barrier for oxygen ions/vacancies causes retention time to be longer in a TiW/Al 2 O 3 /Ta 2 O 5 /Ta device. Multiple memory states were observed and found to be stable for at least 104 s at room temperature and this failure time is defined as the time for the resistance variation to remain within 10%.

Organic–inorganic hybrid perovskite solar cells, which are regarded as the most promising candidate for next-generation photovoltaic cells, have achieved extremely high power conversion efficiencies of over 23%. However, hysteresis, characterized as an inconsistent power output under varying electric fields, hinders their progress towards commercialization. In this paper, by introducing potassium thiocyanate into the perovskite precursor solution, we have successfully obtained a highly efficient methylammonium lead iodide (MAPbI3) perovskite solar cell with no hysteresis. The incorporation of potassium thiocyanate immensely enhances the crystallinity of MAPbI3 with lower defect density and longer carrier lifetime. The grain size increases to over 600 nm due to the positive synergy of potassium ions and thiocyanate ions, which is more than three times compared with that of the control sample. Decreased series resistance and increased recombination resistance reveal faster charge transport and less carrier recombination, respectively, contributing to hysteresis elimination. At the optimum concentration of the potassium thiocyanate additive, the perovskite solar cell achieves a high conversion efficiency of 19.6%.

In this paper, we utilize a two-step solvothermal associated with in-situ ultrasonic precipitation method to construct novel AgCl/g-C3N4 heterostructure nanotube. Thereafter, the structure and morphology of the hybrid was testified by XRD and FE-SEM, indicating that the hybrid was composed of hexagonal phase g-C3N4 and cubic phase AgCl. Furthermore, the AgCl nanoparticles with the average size of 20 nm were completely dispersed on the surface and nozzle of the g-C3N4 nanotube with the average diameter of 100 nm and the average length of 800 nm. Then the decontamination performance of AgCl/g-C3N4 composite was investigated, showing that the AgCl (20%wt)/g-C3N4 composite has higher photocatalytic effect on Rhodamine B (RhB) solution than pure g-C3N4, which has the higher 92% total removal rate of RhB and the larger K value of 0.02827 min−1. The improved photocatalytic performance can be ascribed to the efficient separation and transfer of photo-generated electron-hole at the hybrid interface via a Z-scheme mechanism.

Hybrid organic–inorganic perovskite (HOIP) materials have caught significant attention in photovoltaics and photoelectronics for their outstanding photovoltaic properties. However, their instability to various environment, such as illumination, temperature, moisture and oxygen, hinders their way to commercialization. To figure out the interaction mechanism between H2O and CH3NH3PbI3 (MAPbI3), extensive theoretical studies have been carried out; however, the experimental results are insufficient and inconsistent. Here, we systematically investigate and compare the influence of H2O on MAPbI3 perovskite films with or without DMF) post-annealing in dark or light condition. The interaction between H2O and the surface of pristine MAPbI3 leads to the fusion of grain boundaries thus grain growth into micron level in short-time moisture exposure. While the penetration of H2O into MAPbI3 results in swelled crystalline whisker, cracking into smaller grains in long-time exposure upon the release of H2O. However, no degradation occurs in dark condition. As the DMF post-annealing treatment changes the surface states of MAPbI3, the interactions between the external H2O and internal MAPbI3 significantly varies from the pristine MAPbI3. Three different surface states with different topographies have influence on the interaction process and mechanism with H2O, leading to different decomposition rates, the striped surface that is the most rough among the three and experiencing the minimum change in surface potential with exposure to 80% humidity decomposes into PbI2 fastest. However, the addition of light will once again affect the aforementioned process. It is found that even ambient light could severely speed up the moisture-induced decomposition of MAPbI3, while the N,N-dimethylformamide (DMF) post-annealing treatment significantly improves the stability of MAPbI3 films upon exposure to humidity and illumination, benefiting from the MAI-deficient thus H2O resistant surface.

Recently, numerous efforts have been reported on improving the properties of perovskite absorber, which has a direct and significant influence on the photovoltaic performance of solar cells. In this paper, lead acetate was introduced into stoichiometric lewis acid-base perovskite precursor to prepare high-quality methylammonium lead halide (MAPbI3) perovskite films. The trace lead acetate can facilitate the perovskite crystallization and induce grain size growth. After introducing lead acetate, the perovskite films show higher photoluminescence intensity and longer carrier lifetime due to less traps and defects, which is attributed to the improved film properties. The impedance spectroscopy measurements reveal that the lead acetate can decrease the series resistance and recombination resistance in the perovskite solar cells. As a result, the perovskite solar cells with lead acetate achieve an improved average efficiency of 18.06% (18.86% of best efficiency) compared with 16.87% of average efficiency of the control samples without lead acetate, while the hysteresis behavior is also significantly suppressed with the lead acetate.

Enhancing the in-plane current-induced torque efficiency in inversion-symmetry-breaking ferromagnetic heterostructures is of both fundamental and practical interests for emerging magnetic memory device applications. Here, we present an interface-originated magnetoelectric effect, the orbital Rashba–Edelstein effect, for realizing large torque efficiency in Pt/Co/SiO2/Pt films with strong perpendicular magnetic anisotropy (PMA). The key element is a pronounced Co 3d orbital splitting due to asymmetric orbital hybridization at the Pt/Co and Co/SiO2 interfaces, which not only stabilizes the PMA but also produces a large orbital torque upon the Co magnetization with current injection. The torque efficiency is found to be strongly magnetization direction- and temperature-dependent, and can reach up to 2.83 at room temperature, which is several times to one order of magnitude larger than those previously reported. This work highlights the active role of the orbital anisotropy for efficient torque generation and indicates a route for torque efficiency optimization through orbital engineering., The emerging spintronics applications are hampered by low current-induced torque efficiency in, for example, inversion-symmetry-breaking ferromagnetic heterostructures. Here the authors demonstrate an orbital Rashba-Edelstein effect which can enhance the torque efficiency in Pt/Co/SiO2/Pt films due to the intrinsic Co 3d orbital anisotropy.

In this paper, we firstly prepared V0.13Mo0.87O2.935/MoS2 nanocomposites via in-situ hydrothermal approach based on the NH4VO3 and MoS2 as precursors. The structures and morphologies of the obtained products indicated that the cluster composites have flower-like structure with an average particle size of about 2 µm assembled by regular nanosheets and they were comprised of 2H-MoS2 phase and hexagonal V0.13Mo0.87O2.935 phase. Furthermore, the visible-driven photocatalytic experiment results showed that the V0.13Mo0.87O2.935/MoS2 composites display better degradation ability in contrast to pure MoS2 and the optimal V0.13Mo0.87O2.935 (10 wt%)/MoS2 sample with the largest K value of 0.04908 min−1 showed the most significant total removal rate of Rhodmine B (RhB) is up to 96.72%. Finally, the enhanced photocatalytic activities of the products could be attributed to the suppression of charge recombination by confined space effect.

Herein, we prepared a free-standing nanoporous gold leaf (NPGL) catalyst by simple one-step de-alloying of the Au–Ag alloy. It displays a much higher CO Faradaic efficiency (CO FE) of 90% and current density (mass activity) of 20.51 A g−1 as compared to the nonporous gold foil at −1.2 V (vs. Ag/AgCl).

The surface of poly(p-phenylene benzobisoxazole) (PBO) fibers was modified by a hybrid coating composed of polydopamine (PDA) and the hydrolysis products of 3-aminopropyltrimethoxysilane (KH551) using a facile and environment-friendly mussel-inspired co-deposition strategy. The surface morphologies and chemical composition of the obtained hierarchical reinforcement (PBO@PDA/Si) were measured for confirming the successful deposition of the coating. Compared to untreated PBO fiber, the surface roughness and wettability of PBO@PDA/Si were increased remarkably. Importantly, PBO@PDA/Si showed a 50.2% increase in the interfacial shear strength (IFSS) of resulting composite without any decrease in its tensile strength (TS). In addition, its atomic oxygen (AO) erosion and hydrothermal aging resistances were significantly improved. The “one-step” mussel-inspired surface modification strategy starts from simple chemistry and cheap raw materials, and may provide a novel and versatile design for fabricating multifunctional hierarchical reinforcements.

Hybrid organic-inorganic metal halide perovskite solar cells have attracted widespread attention, owing to their high performance, and have undergone rapid development. In perovskite solar cells, the charge transfer layer plays an important role for separating and transferring photogenerated carriers. In this work, an efficient YCl3 -treated TiO2 electron transfer layer (ETL) is used to fabricate perovskite solar cells with enhanced photovoltaic performance and less hysteresis. The YCl3 -treated TiO2 layers bring about an upward shift of the conduction band minimum (ECBM ), which results in a better energy level alignment for photogenerated electron transfer and extraction from the perovskite into the TiO2 layer. After optimization, perovskite solar cells based on the YCl3 -treated TiO2 layers achieve a maximum power conversion efficiency of about 19.99 % (19.29 % at forward scan) and a steady-state power output of about 19.6 %. Steady-state and time-resolved photoluminescence measurements and impedance spectroscopy are carried out to investigate the charge transfer and recombination dynamics between the perovskite and the TiO2 electron transfer layer interface. The improved perovskite/TiO2 ETL interface with YCl3 treatment is found to separate and extract photogenerated charge rapidly and suppress recombination effectively, which leads to the improved performance.

Metal oxides are used in magnetic tunnel junctions to improve the magnetic properties and thermostability of materials in high-performance applications. In this study, an ultrathin Hf film is deposited on a Ta buffer layer. Moreover, subsequent annealing at 350 °C leads to the oxidation of Hf into HfO 2 , as confirmed by X-ray photoelectron spectrometry (XPS). The effect of HfO 2 on magnetic anisotropy is evaluated in Ta/Hf/CoFeB/MgO/Ta multilayer films. Easy-axis magnetisation transition from in-plane to out-of-plane direction is observed at an annealing temperature of 200 °C. Moreover, the sample annealed at a temperature of 350 °C exhibits clear perpendicular magnetic anisotropy, which satisfies industry requirements in terms of annealing temperature for magnetic random access memory applications. XPS, positron annihilation spectroscopy (PAS), X-ray reflectivity (XRR) and atomic force microscopy (AFM) are used to study film composition, defects, interface width and surface roughness in Ta/Hf/CoFeB/MgO/Ta multilayers. XPS results demonstrate partial suppression of Ta atom diffusion and enhanced formation of Fe (Co)oxides in CoFeB/MgO. The results of PAS analysis suggest that the density of film defects decreases after annealing at 350 °C. XRR and AFM results reveal that annealing at 350 °C produces a smoother CoFeB/MgO interface. Together, these factors lead to improved magnetic properties and thermostability in a Ta/Hf/CoFeB/MgO/Ta film.

The anisotropic magnetoresistance (AMR) and magnetic properties of NiFe films can be remarkably enhanced via CoFeB layer. In the case of an ultrathin NiFe film having a Ta/CoFeB/MgO/NiFe/MgO/CoFeB/Ta structure, the CoFeB/MgO layers suppressed the formation of magnetic dead layers and the interdiffusions and interface reactions between the NiFe and Ta layers. The AMR reached a maximum value of 3.56% at 450 °C. More importantly, a single NiFe (1 1 1) peak can be formed resulting in higher AMR values for films having CoFeB layer. This enhanced AMR also originated from the significant specular reflection of electrons owing to the crystalline MgO layer, together with the sharp interfaces with the NiFe layer. These factors together resulted in higher AMR and improved magnetic properties.

Kudzu is cosmopolitan and low-cost as a source of fiber, food, medicine, and fuel. However, it is not well utilized as a kind of fiber due to the degumming problem. In order to take full advantage of the kudzu resource in the world and expand the application field of kudzu fiber, this study deals with preparation of kudzu fiber by combined steam explosion and chemical degumming. Kudzu fibers are characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. It is found that kudzu fiber after combined degumming has a clean surface with most nonfibrous composition removed and fibers dispersed; the cellulose I structure of kudzu cellulose did not change after treatment but its crystallinity increased. These results suggest this combined degumming is feasible for preparing kudzu fiber. It will probably provide theoretical basis for subsequent utilization of kudzu fibers.

A powerful hard x-ray source based on laser plasma interaction is developed. By introducing the kHz, 800 nm pulses onto a rotating molybdenum (Mo) disk target, intense Mo Kα x-rays are emitted with suppressed bremsstrahlung background. Results obtained with different laser intensities suggest that the dominant absorption mechanism responsible for the high conversion efficiency is vacuum heating (VH). The high degree of spatial coherence is verified. With the high average flux and a source size comparable to the laser focus spot, absorption contrast imaging and phase contrast imaging are carried out to test the imaging capability of the source. Not only useful for imaging application, this compact x-ray source is also holding great potential for ultrafast x-ray diffraction (XRD) due to the intrinsic merits such as femtosecond pulse duration and natural synchronization with the driving laser pulses.

Transport properties of magnetron-sputtered CoO/Co/Pt heterostructures were investigated by physical property measurement system. Different types of magnetoresistance are observed in the heterostructures, including isotropic anisotropic magnetoresistance (AMR), AMR with geometric size effect, and interfacial effect. A reversal in sign of perpendicular AMR is found in the film CoO(3 nm)/Co(3 nm)/Pt(3 nm) compared to the film CoO(3 nm)/Co(3 nm)/CoO(3 nm), which is associated with Pt. Moreover, perpendicular AMR is tunable in the films CoO(3 nm)/Co(3 nm)/CoO(t)/Pt(3 nm) and CoO(3 nm)/Co(3 nm)/Pt(t)/CoO(3 nm) at will, with either positive or negative value, by varying the inserting layer thickness. The electronic structure information of the samples was measured by X-ray photoelectron spectroscopy (XPS). The spin-related transport and XPS results manifest that magnetic proximity effect, surface scattering, together with oxygen migration contribute to the tunable function of Pt.

Spray deposition has been demonstrated to be a promising method to prepare perovskite thin film with many advantages, such as easy and processable under fully ambient condition, which is suitable for large-scale production. In this work, we reveal two typical spray deposition process of rapid and slow solvent evaporation. It is emphasized that the rapid solvent evaporation process is essential to avoid dendritic crystal and obtain dense perovskite thin film without pin-holes, which can be realized with a suitable substrate temperature. With optimized spray conditions including flow rate of precursor solution and carrier gas pressure, a dense and uniform perovskite layer with full surface coverage was immediately formed in similar to 5 s without any post-annealing process. The as-fabricated planar heterojunction solar cell achieved a power conversion efficiency (PCE) of 13.54% with 300 +/- 30 nm in thickness of perovskite layer. To the best of our knowledge, this result is the highest value for the CH3NH3PbI3 perovskite solar cells fabricated in air condition with high humidity up to 50%.

The low-cost inorganic–organic lead halide perovskite materials become particularly promising for solar cells with high photovoltaic conversion efficiency. The uniform and pinhole-free perovskite films play an important role for high-performance solar cells. We demonstrate an antisolvent treatment by controlling the PbI2 morphology to enhance the perovskite conversion and photophysical properties, including high absorption, crystallinity, and rapid carrier transfer. The fabricated perovskite solar cells show tremendous PCE improvement to about 16.1% from 12% with less hysteresis, and retain over 90% initial PCE after 30 days in ambient and dark atmosphere. In prospect, this antisolvent treatment will be a feasible route to prepare high-quality perovskite films including favorite photophysical properties.

Scandium aluminum nitride (ScAlN) thin film has received wide attention for high performance piezo-MEMS device development. This work studies the large-size abnormal grains in the reactive sputtered ScAlN films. Our experimental results prove the abnormal grain nucleates in the normal film matrix and grows larger along the film thickness direction. The local in-plane strain induced by the lattice deformation results in atomic stacking fault, which is suggested to drive the abnormal nucleation.

We report a bipolar $SiO_{2}$-based selector with threshold switching and self-compliance characteristics. The device turns ON under applied voltage of about $\pm 0.6{V}$, and turns OFF when the applied voltage drops below $\pm 0.04{V}$. Engineering of the copper (Cu) supply film is implemented by alloying Cu with $Ge_{2}Sb_{2}Te_{5}(GST)$. This enables appropriate modulation of the Cu concentration and migration in the active $SiO_{2}$ film, which is responsible for the reliable self-compliance bipolar threshold switching.

Corrosion existing in many fields brings lots of troubles to our life. In this work, epoxy coatings modified by hydrophobic nano-silica and hydrophilic nano-silica were fabricated to provide corrosion protection for phosphatized Q235 carbon steel. The traditional epoxy coating was prepared by the polymerization of trimethylolpropane triglycidyl ether and diethylenetriamine. The modified epoxy coating was fabricated by the polymerization and mixing of trimethylolpropane triglycidyl ether, diethylenetriamine and nano-silica. The microscopic morphologies of various epoxy coatings were investigated by SEM. Wettability of epoxy coatings was measured by static contact angle measurement instrument. Thermal stability was tested by thermo gravimetric analyzer. Corrosion behaviors was investigated by electrochemical workstation. Adhesion was reflected by cross-cut test and pull-off test. Equivalent circuits were used to fit the electrochemical impedance spectrum (EIS). According to experimental results, modified epoxy coatings present good hydrophobicity, good thermal stability at 250 °C with only about 3 % weight loss and the ca. 10 μm modified epoxy coating added with the most hydrophobic nano-silica shows the best anticorrosive performance with impedance of 5.25 × 105 Ω•cm2 (0.01 Hz) at 0 h immersion. The anticorrosive performance of epoxy coating is significantly improved when hydrophobic nano-silica is added into epoxy matrix. Adding hydrophobic nano-silica can effectively prolong the diffusion path of water-soluble corrosive medium and the hydrophobicity is able to retard the diffusion of water.

We report a study on the evolution of perpendicular magnetic anisotropy (PMA) in Ta/Mo/CoFeB/MgO/Ta junctions annealed at 350 °C for different periods of time. The PMA quickly developed after a short annealing time followed by a slow approach to saturation. This evolution of PMA was accompanied by structural changes. The surface roughness ( R q ) gradually increased with increasing annealing time to 30 min; further increases in annealing time resulted in a dramatic increase in R q . The effects of film composition and chemical state on magnetic anisotropy in the as-deposited Ta/Mo/CoFeB/MgO/Ta films and annealed films were studied. The X-ray photoelectron spectroscopy results demonstrated that more Fe oxides were formed at the CoFeB/MgO interface after 1 min of annealing compared to in the as-deposited sample, which is critical to obtain the PMA. High-resolution transmission electron microscopy analysis revealed that the CoFeB and MgO layers are predominantly amorphous in sample as-deposited and after 1min annealing. However, the CoFeB and MgO layers are crystallized in sample after 30 and 60 min annealing, which is beneficial to get high PMA.

A large perpendicular anisotropic magnetoresistance (AMR) is obtained in a MgO/Fe/Cu heterostructure, with a maximum AMR ratio of 0.59%. The perpendicular AMR is approximately inversely dependent on the thickness of the Fe layer above 2.5 nm. It can be increased by enhanced structural asymmetry, which implies an interface effect mainly derived from interfacial Rashba spin-orbit scattering in the MgO/Fe/Cu heterostructure. The perpendicular AMR is temperature dependent.

Fiber supercapacitors (FSCs) have great application potential in future smart textiles and portable and wearable electronics because of their flexibility, tiny volume and wearability. Their main limitation, however, is the low energy density when compared with batteries, which seriously restricts their practical application. How to enhance their energy densities while retaining their high power densities is a critical challenge for fiber-shaped supercapacitor development. Here, we first fabricated three-dimensional CNT sponge (3DCS) by a facile electrochemical activation and freeze-drying method and then synthesized 3DCS/polyaniline nanocomposite fibers by in situ electro-polymerization. Through a rational nanoscale electrode engineering design, the resultant fibers show a specific capacitance as high as 242.9 F cm−1 in 1 M H2SO4. Furthermore, a fiber-shaped asymmetric supercapacitor (FASC) was assembled using 3DCS/P as the positive electrode and 3DCS as the negative electrode. After optimization, the FASC delivers a high energy density of 30.92 μW h cm−2, which is about 2 times higher than that of the highest reported previously, and maintains a maximum power density (1.78 mW cm−2) more than two orders of magnitude higher than those of micro-batteries and an outstanding mechanical stability with 90.2% specific capacitance retained after 1000 bending cycles. In view of the excellent electrochemical characteristics and the simple manufacturing of the highly conductive and flexible 3DCS/P, it offers new opportunities for designing long-life wearable FSCs with high energy density and high power density.

Enhancement of post-annealing stability in Co/Ni multilayers with perpendicular magnetic anisotropy (PMA) was obtained by inserting Au layers into Ni/Co interfaces. After annealing at 350 °C, the effective magnetic anisotropy density (K eff) for Ta(3)/Pt(2)/[Co(0.3)/Ni(0.6)/Au(0.3)] × 3/Co(0.3)/Pt(1)/Ta(3) (in nm) keeps at 0.48 × 105 J·m−3. Scanning transmission electron microscopy-high-angle annular dark field (STEM-HAADF) analysis shows that the diffusion between Ni and Co layers is obstructed by the Au insertion layers among them, which is responsible for the post-annealing stability enhancement of the multilayers. Multilayers with Pt insertion layers were also investigated as reference samples in this work. Compared with Pt-layer-inserted Co/Ni multilayers, the Au insertion layers are found to bring seldom interfacial PMA to the multilayers, making it competitive in being employed to enhance the post-annealing stability of PMA Co/Ni multilayers which are used for magnetic random access memory devices (MRAM).

Cellulosic fibers from the bast of Pueraria lobata (P. lobata) vine were separated using a “green” and efficient method that combined steam explosion (SE) and a laccase mediator system (LMS). The chemical components, structure, and thermal alterations in the fibers were evaluated. The SE performed at 180 °C for 10 min did not change the chemical composition of P. lobata; however, SE did alter the fiber structure and rendered its surface more accessible to the laccase enzyme. Treated and untreated samples were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), and chemical methods. The cellulose content of the processed fibers was approximately 68.2%, and the lignin content was 11.8%, which was much lower than the 22.98% lignin content of the raw material. The cellulose fibers exhibited higher cellulose crystallinity and thermal stability compared with the untreated samples. This combined treatment approach may be useful for the isolation of cellulose fibers for composites, textiles, and other industrial applications.

s To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis has been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation, and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent in the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (KCoFeB/MgO). As a result, the perpendicular magnetic anisotropy at high annealing temperatures is maintained

Stretchable and multifunctional sensors can be applied in multifunctional sensing devices, safety forewarning equipment, and multiparametric sensing platforms. However, a stretchable and multifunctional sensor was hard to fabricate until now. Herein, a scalable and efficient fabrication strategy is adopted to yield a sensor consisting of ZnO nanowires and polyurethane fibers. The device integrates high stretchability (tolerable strain up to 150%) with three different sensing capabilities, i.e., strain, temperature, and UV. Typically achieved specifications for strain detection are a fast response time of 38 ms, a gauge factor of 15.2, and a high stability of >10 000 cyclic loading tests. Temperature is detected with a high temperature sensitivity of 39.3% °C−1, while UV monitoring features a large ON/OFF ratio of 158.2. With its fiber geometry, mechanical flexibility, and high stretchability, the sensor holds tremendous prospect for multiparametric sensing platforms, including wearable devices.

Iron-based fluorides are considered as a kind of promising conversion cathode material in Li/Na ion batteries due to its low cost and high theoretical specific capacity. However, the poor electrical conductivity, sluggish reaction kinetics and rapid capacity attenuation during the cyclic process restrict their practical application. Herein, by designing process route and optimizing the reaction conditions, e.g., temperature, reaction time and the concentration of reactants, the raspberry-like micro-sized hierarchical FeF3·0.33H2O spherical material has been successfully prepared through the simple one-step solvothermal method combined with annealing treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and energy-dispersive X-ray spectroscope mapping are employed to characterize the phase composition, crystallinity, morphology and elemental distribution of the as-prepared iron-based fluoride. The results indicate that the as-prepared material presents the pure phase FeF3·0.33H2O with high crystallinity and raspberry-like 3D hierarchical micro-sized sphere morphology. The electrochemical measurements indicate that as the cathode material of Li-ion battery it can deliver a high initial discharge capacity of 438 mAh g−1 and retain 284 mAh g−1 after 100 cycles within a voltage range of 1.5–4.5 V at 0.1C (1C = 200 mA g−1). Meanwhile, as a cathode material of Na-ion battery, it also shows high capacity and good cycle stability. It delivers a discharge capacity of 228 mAh g−1 at 0.1C between 1.5 and 4.5 V. Even at relatively high rate of 2C, a discharge capacity of 101 mAh g−1 after 100 cycles can still be achieved. The excellent lithium/sodium-storage performance of the as-prepared FeF3·0.33H2O material can generally be ascribed to its 3D hierarchical micro-nanostructure.

In recent years, the rapid development of portable and wearable electronic products has promoted the prosperity of fiber supercapacitors (FSCs), which serve as flexible and lightweight energy supply devices. However, research on FSCs is still in its infancy and the energy density of FSCs is far below the level of lithium-ion batteries. Here, we report a facile method to prepare a novel fibrous CNT-aerogel by electrochemical activation and freeze-drying. The fibrous CNT-aerogel electrode possesses a large specific surface area, high mechanical strength, excellent electrical conductivity, as well as a high specific capacitance of 160.8 F g-1 at 0.5 mA and long cycling stability. Then we assembled a non-faradaic FSC based on a fibrous CNT-aerogel as the electrode and a P(VDF-HFP)/EMIMBF4 ionogel as the electrolyte. The introduction of the ionogel electrolyte increases the operating voltage of the FSC to 3 V, and makes the device combine the intrinsic high power density (27.3 kW kg-1) of non-faradaic SCs with an ultrahigh energy density of 29.6 W h kg-1. More importantly, the assembled FSCs show excellent flexibility and bending-stability, and can still operate normally within a wide working temperature window (0-80 °C). The outstanding electrochemical performance and the mechanical/thermal stability indicate that the assembled FSC device is a promising power source for flexible electronics.

Butyl acrylate-α-methyl methacrylate-glycidyl methacrylate (BA-MMA-GMA) terpolymer was successfully grafted onto carbon nanotubes (CNTs) via a facile grafting functionalization approach, affording an organically functionalized multiwalled CNTs (O-MWCNTs), which show improved mechanical and thermal properties in natural rubber/styrene-butadiene rubber (NR/SBR) composites. Under optimized conditions, the result of elongation at break of NR/SBR composites combined with 1.5 parts per hundred rubber (phr) O-MWCNTs is 450% compared to 376% of pristine NR/SBR composites, which is proportional to tensile strength due to the mixed O-MWCNTs in the rubber matrix. Transmission electron microscopy study shows that O-MWCNTs (1.5 phr) can disperse uniformly in NR/SBR/O-MWCNT composites. A scanning electron microscopy study on the fractured surface morphology of the optimized composites reveals that a BA-MMA-GMA terpolymer can interact with the rubber matrix strongly. The decreased height of the maximum tanδ peak shows that O-MWCNTs can reduce the heat buildup and damping capability of NR/SBR/O-MWCNT composites. The largest enhancement observed in the thermal degradation curves of composites is, for the first time, about 70°C, which can be attributed to enhanced interfacial interaction between MWCNTs and the rubber matrix.

Fiber-shaped supercapacitors (FSCs) have attracted significant interest owing to their unique advantages of small size, light weight, high flexibility, and capability of being integrated into wearable electronics and smart textiles. Their main limitation, however, is their low energy density when compared with batteries. Here a fiber-shaped asymmetric supercapacitor (FASC) with high energy density has been developed successfully using CNT@ZnO-NWs@MnO2 fibers as the positive electrode and CNT fibers as the negative electrode. Due to the high capacitances and excellent rate performances of CNT@ZnO-NWs@MnO2 fibers and CNT fibers, such an asymmetric cell exhibits superior electrochemical performances. An optimized FASC can be cycled reversibly in the voltage range of 0–1.8 V, and exhibits a maximum energy density of 13.25 μW h cm−2, which is much higher than those reported for fiber-shaped supercapacitors. Owing to the rational structure design, the all-solid-state FASCs demonstrate excellent mechanical and electrochemical stability. Over 1000 bending cycles, 96.7% of the initial capacitance can still be retained.