Metallic Zinc Anode Working at 50 and 50 mAh cm−2 with High Depth of Discharge via Electrical Double Layer Reconstruction

Achieving high-rate and high-areal-capacity Zn anode with high depth of discharge (DOD) offers a bright future for large-scale aqueous batteries. However, Zn deposition suffers from severe dendrite growth and side reactions, which compromises achievable lifetime. Herein, an electrical double layer (EDL) reconstruction strategy is proposed by employing acetone as electrolyte additive to fully address these issues. Experimental and theoretical simulation results reveal that the adsorption priority of acetone to water on Zn creates a water-poor inner Helmholtz layer. Meanwhile, the intense hydrogen bonding effect between acetone and water confines the activity of free water and weakens the Zn²⁺ solvation in the outer Helmholtz layer and diffusion layer. Such ion/molecule rearrangement in EDL suppresses hydrogen evolution, facilitates the desolvation process, and promotes the Zn²⁺ diffusion kinetics, which guides homogeneous Zn nucleation and uniform growth, even in extreme situations. At both ultrahigh current density of 50 mA cm⁻² and areal capacity of 50 mAh cm⁻², the addition of 20 v/v% acetone in 2 m ZnSO₄ extends the lifespan of Zn//Zn symmetric cells from 12 to 800 h, with a high DOD of 73.5%. The effectiveness of this strategy is further demonstrated in the Zn-MnO₂ full batteries at wide temperature range from −30 to 40 °C.     

Comparative study of low-frequency noise in 0.18 μm and 0.35 μm gate-length nMOSFETs with gate area of 1.1 μm2

We analyzed the noise characteristics of 0.18 μm and 0.35 μm nMOSFETs with a gate area of 1.1 μm² in the frequency range of 1 Hz to 100 kHz. Both two- and four-finger devices were investigated and analyzed. The experimental results show that the noise of 0.35 μm gate-length nMOSFET possesses lower 1/f component than the 0.18 μm one, whereas the four-finger devices reveal less 1/f noise than those of with two-finger ones. Furthermore, we used time domain measurement of drain current and also the statistical analysis of wafer level on the random telegraph signals (RTS) tests, and the results showed that RTS noise is higher in devices with a 0.35 μm gate-length, and devices with a smaller gate finger width produce more RTS noise than devices with a larger gate finger width.     

Band offsets at interfaces of (1 0 0)InxGa1−xAs (0 ⩽ x ⩽ 0.53) with Al2O3 and HfO2

The electron energy band alignment at interfaces of In_xGa_1?xAs (0 ? x ? 0.53) with atomic-layer deposited insulators Al₂O₃ and HfO₂ is characterized using combined measurements of internal photoemission of electrons and photoconductivity. The measured energy of the In_xGa_1?xAs valence band top is found to be only marginally influenced by the semiconductor composition. This result suggests that the observed bandgap narrowing from 1.42 to 0.75 eV when the In content increases from 0 to 0.53 occurs mostly through downshift of the semiconductor conduction band bottom. Electron states originating from the interfacial oxidation of In_xGa_1?xAs lead to reduction of the electron barrier at the semiconductor/oxide interface.     

Antifreezing Zwitterionic Hydrogel Electrolyte with High Conductivity of 12.6 mS cm−1 at −40 °C through Hydrated Lithium Ion Hopping Migration

Hydrogel electrolytes have high room-temperature conductivity and can be widely used in energy storage device. However, hydrogels suffer from the inevitable freezing of water at subzero temperatures, resulting in the diminishment of their conductivity and mechanical properties. How to achieve high conductivity without sacrificing hydrogels’ flexibility at subzero temperature is an important challenge. To address this challenge, a new type of zwitterionic polymer hydrogel (polySH) electrolytes is fabricated. The anionic and cationic counterions on the polymer chains facilitate the dissociation of LiCl. The antifreezing electrolyte can be stretched to a strain of 325% and compressed to 75% at −40 °C and possesses an outstanding conductivity of 12.6 mS cm⁻¹ at −40 °C. A direct hopping migration mechanism of hydrated lithium-ion through the channel of zwitterion groups is proposed. The polySH electrolyte-based-supercapacitor (SC) exhibits a high specific capacitance of 178 mF cm⁻² at 60 °C and 134 mF cm⁻² at −30 °C with a retention of 81% and 71% of the initial capacitance after 10 000 cycles, respectively. The overall merits of the electrolyte will open up a new avenue for advanced ionic conductors and energy storage device in practical applications.     

A Nonflammable Organic Electrolyte with a Weak Association State for Zinc Batteries Operated at −78.5 °C

Traditional rechargeable Zn batteries fail to work in cold regions due to the high freezing point (T_f) and severe corrosivity of the aqueous electrolytes with excessive association (solvent-solvent and solute-solvent interactions). In this study, a nonflammable weak-associated electrolyte (WASE) consisting of ZnCl₂ salt and methanol/dichloromethane mixture as a solvent is developed to achieve high reversible Zn plating/stripping at low temperatures. The low self-association interaction of the mixed solvent not only endures WASE with a low T_f of −119.2 °C but also facilitates the desolvation of interfacial Zn²⁺ and induces smooth Zn plating at low temperatures. Moreover, the water-free WASE inhibits the hydrolysis of ZnCl₂ and thus restrains the corrosion of Zn electrodes. Thanks to the above merits, the Zn||Zn, Zn||Cu, and Zn||polyaniline cells with WASE exhibit superb electrochemical performance at temperatures as low as −78.5 °C.     

Device characteristics of AlGaN/GaN MIS–HEMTs with high-k HfxZr1−xO2 (x = 0.66, 0.47, 0.15) insulator layer

This study investigates the characteristics of AlGaN/GaN MIS–HEMTs with Hf_xZr_1−xO₂ (x = 0.66, 0.47, and 0.15) high-k films as gate dielectrics. Sputtered Hf_xZr_1−xO₂ with a dielectric constant of 20–30 and a bandgap of 5.2–5.71 eV was produced. By increasing the Zr content of HfZrO₂, the V_TH shifted from −1.8 V to −1.1 V. The highest Hf content at this study reduced the gate leakage by approximately one order of magnitude below that of those Zr-dominated HFETs. The maximum I_DS currents were 474 mA/mm, 542 mA/mm, and 330 mA/mm for Hf content of 66%, 47%, 15% at V_GS = 3 V, respectively.     

Active Site Implantation for Ni(OH)2 Nanowire Network Achieves Superior Hybrid Seawater Electrolysis at 1 A cm−2 with Record-Low Cell Voltage

Direct seawater electrolysis provides a grand blueprint for green hydrogen (H₂) technology, while the high energy consumption has severely hindered its industrialization. Herein, a promising active site implantation strategy is reported for Ni(OH)₂ nanowire network electrode on nickel foam substrate by Ru doping (denoted as Ru Ni(OH)₂ NW²/NF), which can act as a dual-function catalyst for hydrazine oxidation and hydrogen evolution, achieving an ultralow working potential of 114.6 mV to reach 1000 mA cm⁻² and a small overpotential of 30 mV at 10 mA cm⁻², respectively. Importantly, using the two-electrode hydrazine oxidation assisted seawater electrolysis, it can drive a large current density of 500 mA cm⁻² at 0.736 V with over 200 h stability. To demonstrate the practicability, a home-made flow electrolyzer is constructed, which can realize the industry-level rate of 1 A cm⁻² with a record-low voltage of 1.051 V. Theoretical calculations reveal that the Ru doping activates Ni(OH)₂ by upgrading d-band centers, which raises anti-bonding energy states and thus strengthens the interaction between adsorbates and catalysts. This study not only provides a novel rationale for catalyst design, but also proposes a feasible strategy for direct alkaline seawater splitting toward sustainable, yet energy-saving H₂ production.     

Deep Insight into Steep-Slope Threshold Switching with Record Selectivity (>4 × 1010) Controlled by Metal-Ion Movement through Vacancy-Induced-Percolation Path: Quantum-Level Control of Hybrid-Filament

This study demonstrates a hyper-level control of metal-ion migration through vacancy-induced-percolation (VIP) path to maximize the steep-slope performance of the threshold selector with excellent selectivity and endurance. Highly efficient control over metal-ion migration through VIP is achieved with sophisticated stack engineering through the material evolution process and refined electrical operation. A thorough analysis of the energetics of metal-ion- and vacancy-based hybrid filament is performed using density functional theory calculations, which leads to a proper tuning of the biasing scheme. Command over bias-induced ion migration to control the atomic-scale filament is the key to maximize the threshold switching (TS) performance. The devices are designed with different diffusive materials and alloys. Precise atomic-level control is realized with optimized device structure and alloy electrode, which indicates that the TS is safe within the vicinity of quantum contact. Owing to the synergistic impact of localized metal-ion injection through VIP, alloy electrode material, and atomic-level filament, the devices exhibit meticulous control of a highly stable TS with a high steep-slope of <2 mV dec⁻¹, extremely high selectivity of >4 × 10¹⁰ with an exceptional endurance >10⁹ cycles, and device yield of 100%, which suggest the applicability of these devices in 1S1R and 1T1R platforms.     

Achieving over 1,000 mW cm−2 Power Density Based on Locally High-Density Cross-Linked Polybenzimidazole Membrane Containing Pillar[5]arene Bearing Multiple Alkyl Bromide as a Cross-Linker

Cross-linking is widely accepted as an effective method to improve the mechanical strength and durability of phosphoric acid (PA) doped polybenzimidazole (PBI) membranes. However, the cross-linked membranes generally exhibit compromised overall performance since their compact network structures decrease the free volumes of membranes, leading to poor proton conductivity. In this study, a locally high-density cross-linked polybenzimidazole network based on pillar[5]arene bearing multiple alkyl bromide is constructed for the first time to achieve high proton conductivity, desired mechanical properties, and excellent fuel cell performance. The pillar[5]arene-cross-linked network considerably enhances the mechanical strength of membrane (14.6 MPa), particularly with high PA uptake, and provides loose PBI chain segment packing to retain PA (315.9%). Surprisingly, the pillar[5]arene-cross-linked PBI membrane displays a high-power density of 1,084.1 mW cm⁻² at 180 °C and 0.6 mg cm⁻² Pt loading without backpressure and humidification, that is the highest value reported in cross-linked membranes for high-temperature proton exchange membrane fuel cells.     

High Performing Solid-State Organic Electrochemical Transistors Enabled by Glycolated Polythiophene and Ion-Gel Electrolyte with a Wide Operation Temperature Range from −50 to 110 °C

The development of organic electrochemical transistors (OECTs) capable of maintaining their high amplification, fast transient speed, and operational stability in harsh environments will advance the growth of next-generation wearable and biological electronics. In this study, a high-performance solid-state OECT (SSOECT) is successfully demonstrated, showing a recorded high transconductance of 220 ± 59 S cm⁻¹, ultrafast device speed of ≈10 kHz with excellent operational stability over 10 000 switching cycles, and thermally stable under a wide temperature range from −50 to 110 °C. The developed SSOECTs are successfully used to detect low-amplitude physiological signals, showing a high signal-to-noise-ratio of 32.5 ± 2.1 dB. For the first time, the amplifying power of these SSOECTs is also retained and reliably shown to collect high-quality electrophysiological signals even under harsh temperatures (−50 and 110 °C). The demonstration of high-performing SSOECTs and its application in harsh environment are core steps toward their implementation in next-generation wearable electronics and bioelectronics.     

Electroluminescence at a wavelength of 1.54 μm in Si:Er/Si structures consisting of a number of <Emphasis Type="Italic">p-n</Emphasis> junctions

A method of connecting several p ⁺-n junctions in the same Si:Er/Si structure is demonstrated; this method makes it possible to increase the electroluminescence intensity at a wavelength of 1.54 μm. The structures have been grown by sublimation molecular-beam epitaxy.     

Delicately Designed Cyano-Siloxane as Multifunctional Additive Enabling High Voltage LiNi0.9Co0.05Mn0.05O2/Graphite Full Cell with Long Cycle Life at 50 °C

Lithium-ion batteries (LIBs) adopting layered oxide cathodes with high nickel content (Ni ≥ 0.9) always suffer from extremely poor cycle life, especially at elevated temperatures and higher charging cut-off voltages. Adding small amounts of functional additives is considered to be one of the most economic and efficacious strategies to resolve this issue. Herein, cyano-groups are introduced innovatively into a siloxane to delicately synthesize a novel cyano-siloxane additive, namely 2,2,7,7-tetramethyl-3,6-dioxa-2,7-disilaoctane-4,4,5,5-tetracarbonitrile (TDSTCN). Encouragingly, 0.5 wt.% TDSTCN additive enables ultrahigh nickel LiNi_0.9Co_0.05Mn_0.05O₂/graphite (NCM90/Gr) full cells with dramatically increased cycle life, especially at an elevated temperature of 50 °C and a high charging cut-off voltage of 4.5 V. The characterizations reveal that the TDSTCN additive can scavenge HF and promote the formation of robust stable interface layers on NCM90 cathode and Gr anode due to the synergistic effects of cyano-groups and Si−O bonds. These results reveal the great significance of designing one single additive with several functional groups in enhancing the comprehensive electrochemical performances of high Ni LIBs.     

Stimulated radiation at a wavelength of 2.5 μm at room temperature from optically excited Cd<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Hg<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Te-based structures

The main requirements for optimization of the MCT-based (Cd _x Hg_{1 − x} Te-based) structures for an increase in the wavelength of the stimulated radiation from them under optical pumping are discussed. The emergence of stimulated radiation in MCT range of 2–2.5 μm at room temperature for optimized MCT structures grown on GaAs substrates using the method of molecular beam epitaxy is shown experimentally. The obtained experimental data are the first results of observation of stimulated radiation from the MCT structures at these wavelengths at room temperature. The gain factor in the active medium measured for this case is very large and attains values of 50 cm⁻¹, which allows one to hope that a further advance to a longer wavelengths is possible.     

Resistive Switching of Memristors Based on (Co40Fe40B20)x(LiNbO3)100 – x Nanocomposite with a LiNbO3 Interlayer: Plasticity and Time Characteristics

Journal of Communications Technology and Electronics - The resistive switching (RS) of metal/nanocomposite/metal (M/NC/M) memristive structures based on the...     

Formation of ncl-Si in the Amorphous Matrix a-SiOx:H Located near the Anode and on the Cathode,Using a Time-Modulated DC Plasma with the (SiH4–Ar–O2) Gas Phase ( $${{{text{C}}}_{{{{{text{O}}}_{2}}}}}$$ = 21.5 mol %)

Semiconductors - The formation of ncl-Si in the amorphous matrix a-SiOx:H using a time-modulated DC plasma at an elevated oxygen content of $${{C}_{{{{{text{O}}}_{2}}}}}$$ = 21.5 mol % in a gas...