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Due to their high similarity to biological ion channels, low power consumption, small footprint, and the fact that they do not require reset circuits, threshold switching memristors have been intensively studied for simulating neurons in neuromorphic chips. Switching speed is one of the key challenges which limit the application of threshold switching memristors in chips. In this study, Ta2O5 threshold switching memristors with high switching speeds were prepared by doping with silver. The results show that 14 wt. % Ag doped Ta2O5 threshold switching memristors exhibit excellent bi-directional threshold switching performance, featuring fast switching speeds (<20 ns, <18 ns), low leakage currents (<10 pA), and high switching ratio (>107). According to the field nucleation theory, the rapid switching speed can be attributed to the low nucleation energy (0.26 eV) of silver within the Ta2O5 matrix, which is achieved by incorporating 14 wt. % Ag during the doping process. Based on Pspice, a LIF (leaky integrate-and-fire) neuron based on the silver nanoparticles doped Ta2O5 threshold switching memristors is built, and its firing function has been simulated. The results show that the LIF neuron with a short switching time is able to excite pulse spiking with high frequencies. These results demonstrated that the silver nanoparticles doped Ta2O5-based threshold switching memristors hold significant potential for constructing high-speed artificial neural networks. [ABSTRACT FROM AUTHOR]

This paper investigates the temperature-dependent effects of gamma-ray irradiation on β-Ga2O3 vertical Schottky barrier diodes (SBDs) under a 100 V reverse bias condition at a total dose of 1 Mrad(Si). As the irradiation dose increased, the radiation damage became more severe. The total ionizing dose (TID) degradation behavior and mechanisms were evaluated through DC, capacitance–voltage (C-V), and low-frequency noise (LFN) measurements by varying irradiation, and the test results indicated that TID effects introduced interface defects and altered the carrier concentration within the material. The impact of TID effects was more pronounced at lower temperatures compared to higher temperatures. Additionally, the annealing effect in the high-temperature experimental conditions ameliorated the growth of interface trap defects caused by irradiation. These results suggest that compared to low-temperature testing, the device exhibits higher TID tolerance after high-temperature exposure, providing valuable insights for in-depth radiation reliability studies on subsequent related devices. [ABSTRACT FROM AUTHOR]

The flexible memristor synapses based on binary metal oxides have significant potential in building artificial neural networks to meet people's demands. To obtain flexible memristor synapses with high linearity of conductance update, herein, the effect of Al doping and SiOx layer adding on the flexible TiOx‐based memristor synapse even under bending is studied. The results show that the doping Al and adding SiOx layer improves the linearity of conductance update by 3 times. The bending test results of the SiOx/Al:TiOx‐based memristor synapse show that the linearity decreases slightly with the decrease of the bending radius. When the bending radius is reduced to 5 mm, the total nonlinearity (NL) value of the device is about 0.42. It is still much smaller than the total NL value of TiOx‐based memristor synapse in flat state (about 0.76). The test results of conducting atomic force microscopy show that the improvement of linearity is due to the optimization of conductive filaments. The results provide a feasible program for improving linearity of TiOx‐based flexible memristor synapse even under bending, which can support for the development of high‐performance binary metal oxide flexible memristor synapse. [ABSTRACT FROM AUTHOR]

With the development of the miniaturization of electronic devices, controlling heat dissipation has become a key factor, which affects the service life of devices and energy utilization efficiency. Therefore, it is particularly important to study the heat conduction mechanism of nanomaterials inside microelectronic devices. Herein, the thermal conductivity of MoS2 and graphene/MoS2 heterojunctions using the bond‐order–length–strength theory and the local bond average method is quantitatively analyzed; the functional relationship between the thermal conductivity and the number of layers, temperature, and pressure is established; and the variation trend of thermal conductivity of materials with these factors is studied. The results show that the thermal conductivity of MoS2 and graphene/MoS2 heterojunctions is inversely proportional to the number of layers and temperature, proportional to the pressure. The work provides a simple and effective method for the study of thermal transport properties of 2D materials and heterojunction systems from the perspective of chemical bonding changes at the atomic level. [ABSTRACT FROM AUTHOR]

The performance degradation of a TiO2-film-based RRAM (resistive random access memory) is investigated in a proton irradiation experiment with an energy of 25 MeV. The results reveal that the fabricated Au/TiO2 film/Ti devices exhibit typical I–V of bipolar resistive switching behavior under an irradiation of 1 × 1011 protons/cm2. The low-resistance state (LRS) resistance remains nearly constant, but the high-resistance state (HRS) resistance decreases with an increasing proton fluence. The value of the HRS resistance decreases by approximately one order of magnitude when the value of proton fluence reaches 1 × 1011 protons/cm2. Moreover, the SET voltage decreases with a decreasing proton fluence, while the RESET voltage remains almost constant. Material characterization via x-ray photoelectron spectroscopy demonstrates that the decrease in SET voltage and HRS resistance is mainly caused by radiation-induced oxygen vacancies and non-lattice oxygen. Based on the Voltage Threshold Adaptive Memristor model, a mathematical model of the I–V curve which demonstrates the variation in the RRAM resistance and voltage as a function of proton irradiation is constructed. The simulation results conformed to the experimental results under different proton fluences. Our results form a fundamental guide for the study of radiation performance degradation and radiation hardening of the RRAM with oxygen vacancy conducting filament. [ABSTRACT FROM AUTHOR]

The use of inorganic salt composite nanomaterials to form nanocomposite humidity‐sensing materials is considered to be an effective way to promote the integral performances of humidity sensors. In this work, by combining the advantages of SnSe nanosheet and LiCl, a novel composite structure of LiCl nanoparticles and SnSe nanosheet (LiCl:SnSe nanosheet) is constructed as the humidity‐sensing materials in humidity sensors. Compared with the properties of a resistance‐type humidity sensor based on SnSe nanosheet, the integral humidity‐sensing properties of LiCl:SnSe nanosheet are improved, especially in response and recovery times (shorten to 12 s/4 s) and sensitivity (up to 3.21 × 105%). These results indicate that LiCl:SnSe nanosheet may be a potential humidity‐sensing material for fabricating humidity sensors with high performance. [ABSTRACT FROM AUTHOR]

The negative differential resistance (NDR) effect enables multilevel storage and gradual resistance modulation in resistive switching (RS) devices to be achieved. However, the poor reproducibility of NDR is the obstacle that restricts their application because the appearance of the NDR effect in RS devices is usually accidental or unstable at room temperature. In this report, we demonstrate a polarization and interfacial defect modulated NDR effect in h-LuFeO3/CoFe2O4 heterojunction-based RS devices; especially, the NDR is reproducible after hundreds of cycles at room temperature. This research provides an effective way for realizing the reproducible NDR effect in ferroelectric RS devices, and it may promote the development and application of RS devices with the NDR effect. [ABSTRACT FROM AUTHOR]

Resistive switching devices are currently the best candidates realizing high-density flexible electronics for artificial intelligence because of simple structures, high density, high speed, and low-power consumption. However, few resistive switching devices contain both short-term memory and long-term memory behaviors for the cells connecting control system and machinery parts in artificial intelligence. Here, we report a SrTiO3-based flexible device with mica substrate, in which both short-term and long-term memory behaviors can be achieved. In the effect of a suitable operation, the device can be switched from a short-term memory device to a total long-term memory device. The ON/OFF state of the long-term memory behavior can be stable more than when the device is flat or with bending radius of 4 mm, 6 mm and 8 mm. The results may promote the investigation of the resistive switching devices for high-density flexible electronics with special function. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity worldwide. Cigarette smoking, which leads to abnormalities in the airways or alveoli and persistent obstruction of the airway's flow, is a significant risk factor of COPD. Cryptotanshinone (CTS) is the active ingredient in Salvia miltiorrhiza (Danshen) and has many pharmacological properties including anti-inflammatory, antitumor, and antioxidant properties, but its impact on COPD is uncertain. In the present study, the potential effect of CTS on COPD was investigated in a modified COPD mice model induced with cigarette smoke (CS) and lipopolysaccharide (LPS) exposure. CTS significantly reversed the decline in lung function, emphysema, inflammatory cell infiltration, small airway remodeling, pulmonary pathological damage, and airway epithelial cell proliferation in CS- and LPS-exposed mice. Additionally, CTS decreased inflammatory cytokines such as tumor necrosis factor α (TNF α), interleukins IL-6 and IL-1β, and keratinocyte chemoattractant (KC), increased the activities of superoxide dismutase (SOD), Catalase (CAT) and L -Glutathione (GSH), and repressed the expression of protein hydrolases matrix metalloprotein (MMP)− 9 and − 12 in pulmonary tissue and bronchoalveolar lavage fluid (BALF). The protective effects of CTS were also observed in human bronchial epithelial cell line BEAS-2B simulated with cigarette smoke condensate (CSC) and LPS. Mechanistically, CTS can repress the protein level of Keap1, resulting to activation of erythroid 2-related factor (Nrf2), finally alleviating COPD. In summary, the present findings demonstrated that CTS dramatically ameliorates COPD induced by CS and LPS via activating Keap1/Nrf2 pathway. [Display omitted] • Firstly, cryptotanshinone was found to have good therapeutic effect in COPD. This study demonstrated that cryptotanshinone can treat COPD by regulating Keap1/Nrf2 pathway. • Animal model innovation: using CS oral and nasal inhalation exposure method combined with nasal drip LPS to construct a mouse COPD model. The smoking machine is connected to the animal oral and nasal inhalation exposure system, and the smoking machine simulates the process of human smoking and delivers smoke to the mice. The nicotine exposure concentration was quantified, which made the animal model more scientific and better simulated the disease process of COPD induced by human smoking. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries are recognized as high energy density systems. However, due to the reproducibility of nonpolar S8, polar polysulfide intermediates and the final Li2S during cycling, developing an effective matrix to reduce sulfur consumption in the cathode and improve the cycle stability is still challenging. Herein, a polar and nonpolar matrix consisting of twined multiwalled carbon nanotube (MWCNT) and high nitrogen‐doped porous carbon is designed, in which the twined MWCNT could provide the nonpolar and physical bind, meanwhile, the N‐enriched porous carbon derived from ionic liquid could provide polar and chemical anchoring. The composite is prepared by carbonizing the 1‐ethyl‐3‐methylimidazolium dicyanamide (Emim‐dca) ionic liquid, which is loaded on the intertwined MWCNT. The ionic‐liquid‐derived composite material shows more microporous and low‐diameter mesoporous structures than intertwined MWCNT, and the nitrogen content reaches 7.42 At%. Assembled in lithium–sulfur batteries, the specific capacity of the battery reaches 1558.6 mAh g−1 at the first cycle of 0.1 C. After the 300 times cycling at 1 C, the specific capacity still remains 614.34 mAh g−1 and the attenuation is only 0.021% for each cycle. Moreover, the attenuation in the changing rate charge–discharge test is weaker than the pure intertwined MWCNT composite cathode. [ABSTRACT FROM AUTHOR]

In this study, cadmium sulfide (CdS) and antimony sulfide (Sb2S3) quantum dot (QD) co-sensitized solar cells were fabricated using iodine-based gel polymer electrolytes. It was noticed that in comparison with TiO2/Sb2S3 QDs, the short-circuit current (Jsc) and the photoconversion efficiency (η) of the fabricated photovoltaic device based on TiO2/CdS/Sb2S3 QDs increased from 5.61 to 8.35 mA/cm2 and 1.06-1.61%, respectively. The presence of a CdS buffer layer between TiO2 and Sb2S3 was attributed to the enhancement of Jsc and η. The CdS buffer layer promoted the growth of Sb2S3 and facilitated the transfer of electrons from Sb2S3 to TiO2 through the reorganization of band levels between CdS and Sb2S3. It was also observed that the polymer electrolytes effectively prevented the corrosion of Sb2S3 QDs. Therefore, it can be concluded that the outcomes of this research could expedite future work on novel Sb2S3 quantum dot sensitized solar cells (QDSCs) based on polymer electrolytes with improved performance. [ABSTRACT FROM AUTHOR]

W-Sb-Te phase-change material has been proposed to improve the performance of phase-change memory (PCM). Crystallization temperature, crystalline resistance, and 10-year data retention of Sb2Te increase markedly by W doping. The Wx(Sb2Te)1-x films crystallize quickly into a stable hexagonal phase with W uniformly distributing in the crystal lattice, which ensures faster SET speed and better operation stability for the application in practical device. PCM device based on W0.07(Sb2Te)0.93 shows ultrafast SET operation (6 ns) and good endurance (1.8 × 105 cycles). W-Sb-Te material is a promising candidate for the trade-off between programming speed and data retention. [ABSTRACT FROM AUTHOR]

A sustainable polymer/nanomagnetic (PVDF/Fe 3 O 4) composite nanofiber membrane is prepared on the Al current collector using electrospinning to serve as matrix for sulfur. The paramagnetic adsorption of polysulfides by Fe 3 O 4 can suppress the shuttling effect, and the PVDF reserves as an elastic skeleton for alleviating volume changes of sulfur cathode. The results show that the cathode with PVDF/Fe 3 O 4 composite nanofiber membrane has an initial discharge capacity of 1555.5 mA h g−1 at a rate of 0.1 C, and remains at 994.7 mA h g−1 after 300 cycles, showing a better cycle life than others without Fe 3 O 4 or PVDF. This work provides a strategy for further promoting the commercialization of lithium-sulfur batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

Negative capacitance effects with fast response times hold great potential for reducing the power consumption in high-frequency nanoelectronics. Nevertheless, the negative capacitance effect faces considerable complexity arising from the dynamic interplay among electrostatic, nucleation energies, and domain evolution. This intricate balance poses a formidable challenge to achieving fast negative capacitance. Herein, we have achieved a fast negative capacitance time of ∼16.23 ns in PbZr 0.2 Ti 0.8 O 3 (PZT) thin film, and our investigation confirms the presence of acicular ferroelastic domains within the PZT thin film. Under reversal electric fields, these acicular ferroelastic domains undergo a unique flipping process, transitioning through domain expansion and contraction. This distinct domain flipping manner accelerates the nucleation and growth of ferroelectric domains, thereby facilitating the observed fast negative capacitance. The realization of fast negative capacitance holds substantial promise for reducing operational time and power consumption, offering prospects for the design of nanoelectronics with significantly lower power requirements.

Aqueous zinc-ion batteries are considered potential large-scale energy storage systems due to their low cost, environmentally friendly nature, and high safety. However, the development of high energy density cathode materials and uncertain reaction mechanisms remains a major challenge. In this work, the reaction mechanism, discharge voltage and diffusion properties of layered CrO 2 as a cathode material for aqueous zinc-ion batteries were studied using first-principles calculations, and the effect of pre-intercalated structural water on the electrochemical performance of CrO 2 electrodes is also discussed. The results show that CrO 2 exhibits high average discharge voltages (2.65 V for H insertion (pH = 7) and 1.97 V for Zn insertion) and medium theoretical capacities (319 mA h g -1 (H and Zn)). The H intercalation voltage strongly depends on the pH value of the electrolyte. The H/Zn co-insertion mechanism occurs at low hydrogen concentrations ( c (H) ≤ 0.125), where the initial insertion of H reduces the total amount of subsequent Zn insertion. For the substrate containing structured water (CrO 2 · n H 2 O, n ≥ 0.5), the average voltage of Zn insertion is significantly increased, while the average voltage of H slightly decreases. In addition, the pre-intercalated water strategy significantly improved the diffusion properties of H and Zn. This study shows that layered CrO 2 · n H 2 O is a promising cathode material for aqueous zinc-ion batteries, and also provides theoretical guidance for the development of high-performance cathode materials for aqueous zinc-ion batteries.

The characteristic of self-recovery holds significant implications for upholding performance stability within flexible electronic devices following the release of mechanical deformation. Herein, the dynamics of self-recovery in a buckling inorganic membrane is studied via in situ scanning probe microscopy technology. The experimental results demonstrate that the ultimate deformation ratio of the buckling BaTiO 3 ferroelectric membrane is up to 88%, which is much higher than that of the buckling SrTiO 3 dielectric membrane (49%). Combined with piezoresponse force microscopy and phase-field simulations, we find that ferroelectric domain transformation accompanies the whole process of buckling and self-recovery of the ferroelectric membrane, i.e., the presence of the nano- c domain not only releases part of the elastic energy of the membrane but also reduces the interface mismatch of the a / c domain, which encourages the buckling ferroelectric membrane to have excellent self-recovery properties. It is conceivable that the evolution of ferroelectric domains will play a greater role in the regulation of the mechanical properties of ferroelectric membranes and flexible devices.

The negative differential resistance (NDR) effect enables multilevel storage and gradual resistance modulation in resistive switching (RS) devices to be achieved. However, the poor reproducibility of NDR is the obstacle that restricts their application because the appearance of the NDR effect in RS devices is usually accidental or unstable at room temperature. In this report, we demonstrate a polarization and interfacial defect modulated NDR effect in h-LuFeO 3 /CoFe 2 O 4 heterojunction-based RS devices; especially, the NDR is reproducible after hundreds of cycles at room temperature. This research provides an effective way for realizing the reproducible NDR effect in ferroelectric RS devices, and it may promote the development and application of RS devices with the NDR effect.