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The most reported two-dimensional (2D) reconfigurable multivalued logic (RMVL) devices primarily involve a planar configuration and carrier transport, which limits the high-density circuit integration and high-speed logic operation. In this work, the vertical transistors with reconfigurable MoTe2 homojunction are developed for low-power, high-speed, multivalued logic circuits. Through top/bottom dual-gate modulation, the transistors can be configured into four modes: P-i-N, N-i-P, P-i-P, and N-i-N. The reconfigurable rectifying and photovoltaic behaviors are observed in P-i-N and N-i-P configurations, exhibiting ideal diode characteristics with a current rectification ratio over 105 and sign-reversible photovoltaic response with a photoswitching ratio up to 7.44 × 105. Taking advantage of the seamless homogeneous integration and short vertical channel architecture, the transistor can operate as an electrical switch with an ultrafast speed of 680 ns, surpassing the conventional p-n diode. The MoTe2 half-wave rectifier is then applied in high-frequency integrated circuits using both square wave and sinusoidal waveforms. By applying an electrical pulse with a 1/4 phase difference between two input signals, the RMVL circuit has been achieved. This work proposes a universal and reconfigurable vertical transistor, enabled by dual-gate electrostatic doping on top/bottom sides of MoTe2 homojunction, suggesting a high integration device scheme for high-speed RMVL circuits and systems.

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Sensing platforms with high interference immunity and low power consumption are crucial for the co-detection of dual oxidative stress biomarkers and clinical diagnosis of periodontitis. Herein, we constructed a bifunctional nanozyme to identify hydrogen peroxide (H2O2) and ascorbic acid (AA) with low crosstalk at zero or low bias voltage. To target H2O2 and AA, Fe(III) meso-tetra(4-carboxyphenyl) porphine (TCPP(Fe)) and Pt nanoclusters were selected as active sites respectively, and titanium carbide nanosheets were additionally introduced as a sensitizer. Due to their highly efficient catalytic properties, self-powered detection of H2O2 without bias voltage and distinguishable AA detection at 0.45 V were successfully achieved. Density functional theory calculations further confirmed the binding sites for target molecules and elucidated the sensing mechanism. On this basis, a dual-channel screen-printed electrode was fabricated to further ensure the discriminative detection of dual biomarkers at the device level. The constructed flexible, low-power consumption sensing platform was successfully applied to raw clinical samples, effectively distinguishing between healthy individuals and patients with varying degrees of periodontitis. This work is expected to provide new insights into the design of highly specific nanozymes and low-power consumption electrochemical sensing systems, which will contribute to the accurate and convenient diagnosis of periodontitis.

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Micro-light-emitting diodes (µLEDs) have gained significant interest as an activation source for gas sensors owing to their advantages, including room temperature operation and low power consumption. However, despite these benefits, challenges still exist such as a limited range of detectable gases and slow response. In this study, we present a blue µLED-integrated light-activated gas sensor array based on SnO2 nanoparticles (NPs) that exhibit excellent sensitivity, tunable selectivity, and rapid detection with micro-watt level power consumption. The optimal power for µLED is observed at the highest gas response, supported by finite-difference time-domain simulation. Additionally, we first report the visible light-activated selective detection of reducing gases using noble metal-decorated SnO2 NPs. The noble metals induce catalytic interaction with reducing gases, clearly distinguishing NH3, H2, and C2H5OH. Real-time gas monitoring based on a fully hardware-implemented light-activated sensing array was demonstrated, opening up new avenues for advancements in light-activated electronic nose technologies.

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Nano air channel transistors (NACTs) provide numerous advantages over traditional silicon devices, including faster switching speeds, higher operating frequencies, and enhanced radiation hardness attributable to the ballistic transport of electrons. In the development of field-emission-based integrated circuits, low-power consumption rectifying nano air channel diodes (NACDs) play a crucial role. However, achieving rectification characteristics in NACDs is challenging due to their structural and material symmetry. This paper proposes a vertical GaN NACD with a consistent nano air channel fabricated using IC-compatible processes. The GaN NACD exhibits an exceptionally low turn-on voltage of 0.3 V while delivering a high output current of 5.02 mA at 3 V. Notably, it demonstrates a high rectification ratio of up to 2.2 × 105, attributing to significant work function disparities within the GaN-Au structure, coupled with the reduction of Au surface roughness to minimize reverse current. Furthermore, the junction-free structure and superior material properties of GaN enable the NACD to be suitable for use in radiation-rich environments. With its potential as a fundamental component of ultrafast and ultrahigh-frequency integrated circuits, this intriguing and cost-effective rectifying diode is anticipated to garner widespread interest within the electronics community.

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The use of two-dimensional materials and van der Waals heterostructures holds great potential for improving the performance of memristors Here, we present SnS2/MoTe2heterostructure synaptic transistors. Benefiting from the ultra-low dark current of the heterojunction, the power consumption of the synapse is only 19pJ per switching under 0.1 V bias, comparable to that of biological synapses. The synaptic device based on the SnS2/MoTe2demonstrates various synaptic functionalities, including short-term plasticity, long-term plasticity, and paired-pulse facilitation. In particular, the synaptic weight of the excitatory postsynaptic current can reach 109.8%. In addition, the controllability of the long-term potentiation and long-term depression are discussed. The dynamic range (Gmax/Gmin) and the symmetricity values of the synaptic devices are approximately 16.22 and 6.37, and the non-linearity is 1.79. Our study provides the possibility for the application of 2D material synaptic devices in the field of low-power information storage.

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To reduce the power consumption of a TDC in high-speed applications, a TDC architecture applied to SS ADC is proposed to reduce redundant counting. This structure can remove the identical part between two rows of pixel signals in a CMOS image sensor by adjusting the start and stop signal of the TDC, which will reduce the number of flipping of D flip-flops in the TDC. This structure requires the simultaneous readout of two rows of pixels in the high-speed CMOS image sensor. In the 110 nm CMOS process, simulation results show that the designed 5-bit TDC achieves an effective number of bits (ENOB) at 4.72 bits and a figure-of-merit (FOM) at 104.7-162.3 fJ/step, with a power consumption ranging from 60 µW to 93 µW. Compared with traditional counting methods, the proposed TDC can reduce counting power consumption by 30%.

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Green hydrogen generation technologies are currently the most pressing worldwide issues, offering promising alternatives to existing fossil fuels that endanger the globe with growing global warming. The current research focuses on the creation of green hydrogen in alkaline electrolytes utilizing a Ni-Co-nano-graphene thin film cathode with a low overvoltage. The recommended conditions for creating the target cathode were studied by electrodepositing a thin Ni-Co-nano-graphene film in a glycinate bath over an iron surface coated with a thin copper interlayer. Using a scanning electron microscope (SEM) and energy-dispersive X-ray (EDX) mapping analysis, the obtained electrode is physically and chemically characterized. These tests confirm that Ni, Co, and nano-graphene are homogeneously dispersed, resulting in a lower electrolysis voltage in green hydrogen generation. Tafel plots obtained to analyze electrode stability revealed that the Ni-Co-nano-graphene cathode was directed to the noble direction, with the lowest corrosion rate. The Ni-Co-nano-graphene generated was used to generate green hydrogen in a 25% KOH solution. For the production of 1 kg of green hydrogen utilizing Ni-Co-nano-graphene electrode, the electrolysis efficiency was 95.6% with a power consumption of 52 kwt h-1, whereas it was 56.212. kwt h-1 for pure nickel thin film cathode and 54. kwt h-1 for nickel cobalt thin film cathode, respectively.

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In this study, we demonstrated the effective separation of charge carriers within the IGZO/IZO heterostructure by incorporating IZO. We have chosen IGZO for its high mobility and excellent on-off switching behavior in the front channel of our oxide-oxide heterostructure. Similarly, for an additional oxide layer, we have selected IZO due to its outstanding electrical properties. The optimized optoelectronic characteristics of the IGZO/IZO phototransistors were identified by adjusting the ratio of In:Zn in the IZO layer. As a result, the most remarkable traits were observed at the ratio of In:Zn = 8:2. Compared to the IGZO single-layer phototransistor, the IGZO/IZO(8:2) phototransistor showed improved photoresponse characteristics, with photosensitivity and photoresponsivity values of 1.00 × 107 and 89.1 AW-1, respectively, under visible light wavelength illumination. Moreover, the electrical characteristics of the IGZO/IZO(8:2) transistor, such as field effect mobility (µsat) and current on/off ratio (Ion/Ioff), were highly enhanced compared to the IGZO transistor. The µsat and Ion/Ioff were increased by about 2.1 times and 2.3 times, respectively, compared to the IGZO transistor. This work provides an approach for fabricating visible-light phototransistors with elevated optoelectronic properties and low power consumption based on an oxide-oxide heterostructure. The phototransistor with improved performance can be applied to applications such as color-selective visible-light image sensors and biometric sensors interacting with human-machine interfaces.

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Underground displacement monitoring is a crucial means of preventing geological disasters. Compared to existing one-dimensional methods (measuring only horizontal or vertical displacement), the underground displacement three-dimensional measurement method and monitoring system proposed by the author's research team can more accurately reflect the internal movement of rock and soil mass, thereby improving the timeliness and accuracy of geological disaster prediction. To ensure the reliability and long-term operation of the underground displacement three-dimensional monitoring system, this article further introduces low-power design theory and Bluetooth wireless transmission technology into the system. By optimizing the power consumption of each sensing unit, the current during the sleep period of a single sensing unit is reduced to only 0.09 mA. Dynamic power management technology is employed to minimize power consumption during each detection cycle. By using Bluetooth wireless transmission technology, the original wired communication of the system is upgraded to a relay-type wireless network communication, effectively solving the problem of the entire sensing array's operation being affected when a single sensing unit is damaged. These optimized designs not only maintain monitoring accuracy (horizontal and vertical displacement errors not exceeding 1 mm) but also enable the monitoring system to operate stably for an extended period under harsh weather conditions.

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We propose a new methodology for long-term biopotential recording based on an MEMS multisensor integrated platform featuring a commercial electrostatic charge-transfer sensor. This family of sensors was originally intended for presence tracking in the automotive industry, so the existing setup was engineered for the acquisition of electrocardiograms, electroencephalograms, electrooculograms, and electromyography, designing a dedicated front-end and writing proper firmware for the specific application. Systematic tests on controls and nocturnal acquisitions from patients in a domestic environment will be discussed in detail. The excellent results indicate that this technology can provide a low-power, unexplored solution to biopotential acquisition. The technological breakthrough is in that it enables adding this type of functionality to existing MEMS boards at near-zero additional power consumption. For these reasons, it opens up additional possibilities for wearable sensors and strengthens the role of MEMS technology in medical wearables for the long-term synchronous acquisition of a wide range of signals.

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In this work, we proposed a laser-induced current (LIC) method to investigate the grain-size dependence of the plasma of table sugar induced by a nanosecond (ns) pulsed ultraviolet laser in the size range of <180 µm->550 µm and achieve the lower power consumption in measurement. Under multiple laser irradiations and an external electric field (Vb) of 200 V, the LIC variation's (ΔIp) standard deviation and variance were 0.53 nA and 0.05 nA, respectively, indicating the relatively small systematic error during the testing process. The Vb causes a decrease in the possibility of electron-ion complexation and accelerates the separation, resulting in an increase in ΔIp with Vb. With increasing grain size (diameter D) of table sugar, ΔI demonstrate a valley-like behaviour and 250-380 µm is the critical range Dc where ΔI is very weak and considerably depends on the Vb with the slope of 0.031 nA/V. At D > 550 µm and Vb = 5 V, ΔI intensities monotonically rise by 30 % when D surpasses Dc. In this instance, the energy was the main contributor to the LIC signal during plasma generation and expansion. While D is less than Dc, ΔIp increases by 27 % at D ≤ 180 µm and Vb = 5 V. The yield stress is the main reason for the formation of plasma with high temperature and density in this situation because the sugar behaves like an elastic solid. The reason for such a LIC variation trend was discussed, which can be explained by considering the morphological, thermal and mechanical properties competing with each other. The present result suggests that the LIC method enables non-contact characterisation of sugar particle size at low-power consumption.

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Hazardous substances produced by anthropic activities threaten human health and the green environment. Gas sensors, especially those based on metal oxides, are widely used to monitor toxic gases with low cost and efficient performance. In this study, electron beam lithography with two-step exposure was used to minimize the geometries of the gas sensor hotplate to a submicron size in order to reduce the power consumption, reaching 100 °C with 0.09 W. The sensing capabilities of the ZnO nanofilm against NO2 were optimized by introducing an enrichment of oxygen vacancies through N2 calcination at 650 °C. The presence of oxygen vacancies was proven using EDX and XPS. It was found that oxygen vacancies did not significantly change the crystallographic structure of ZnO, but they significantly improved the electrical conductivity and sensing behaviors of ZnO film toward 5 ppm of dry air.

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High-performance artificial synapse with nonvolatile memory and low power consumption is a perfect candidate for brainoid intelligence. Unfortunately, due to the energy barrier paradox between ultra-low power and nonvolatile modulation of device conductances, it is still a challenge at the moment to construct such ideal synapses. Herein, a proton-reservoir type 4,4',4″,4'''-(Porphine-5,10,15,20-tetrayl) tetrakis (benzenesulfonic acid) (TPPS) molecule and fabricated organic protonic memristors with device width of 10 µm to 100 nm is synthesized. The occurrence of sequential proton migration and interfacial self-coordinated doping will introduce new energy levels into the molecular bandgap, resulting in effective and nonvolatile modulation of device conductance over 64 continuous states with retention exceeding 30 min. The power consumptions of modulating and reading the device conductance approach the zero-power operating limits, which range from 16.25 pW to 2.06 nW and 6.5 fW to 0.83 pW, respectively. Finally, a robust artificial synapse is successfully demonstrated, showing spiking-rate-dependent plasticity (SRDP) and spiking-timing-dependent plasticity (STDP) characteristics with ultra-low power of 0.66 to 0.82 pW, as well as 100 long-term depression (LTD)/potentiation (LTP) cycles with 0.14%/0.30% weight variations.

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We experimentally demonstrate Si-based electrolyte-gated transistors (EGTs) for detecting urea. The top-down-fabricated device exhibited excellent intrinsic characteristics, including a low subthreshold swing (SS) (~80 mV/dec) and a high on/off current ratio (~107). The sensitivity, which varied depending on the operation regime, was analyzed with the urea concentrations ranging from 0.1 to 316 mM. The current-related response could be enhanced by reducing the SS of the devices, whereas the voltage-related response remained relatively constant. The urea sensitivity in the subthreshold regime was as high as 1.9 dec/pUrea, four times higher than the reported value. The extracted power consumption of 0.3 nW was extremely low compared to other FET-type sensors.

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Quantum dot light-emitting diodes (QLEDs) are an emerging class of optoelectronic devices with a wide range of applications. However, there still exist several drawbacks preventing their applications, including long-term stability, electron leakage, and large power consumption. To circumvent the difficulties, QLEDs based on a self-assembled hole transport layer (HTL) with reduced device complexity are proposed and demonstrated. The self-assembled HTL is prepared from poly[3-(6-carboxyhexyl)thiophene-2,5-diyl] (P3HT-COOH) solution in N,N-dimethylformamide (DMF) forming a well-ordered monolayer on an indium-tin-oxide (ITO) anode. The P3HT-COOH monolayer has a smaller HOMO band offset and a sufficiently large electron barrier with respect to the CdSe/ZnS quantum dot (QD) emission layer, and thus it is beneficial for hole injection into and electron leakage blocking from the QD layer. Interestingly, the QLEDs exhibit an excellent conversion efficiency (97%) in turning the injected electron-hole pairs into light emission. The performance of the resulting QLEDs possesses a low turn-on voltage of +1.2 V and a maximum external quantum efficiency of 25.19%, enabling low power consumption with high efficiency. Additionally, those QLEDs also exhibit excellent long-term stability without encapsulation with over 90% luminous intensity after 200 days and superior durability with over 70% luminous intensity after 2 h operation under the luminance of 1000 cd m-2. The outstanding device features of our proposed QLEDs, including low turn-on voltage, high efficiency, and long-term stability, can advance the development of QLEDs toward facile large-area mass production and cost-effectiveness.

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Room-temperature phosphorescence (RTP) two-dimensional (2D) organic-inorganic hybrid perovskites (OIHPs) that possess superior stability and efficient triplet energy transfer between inorganic parts and organic cations have been seen as promising materials in optoelectronic devices. However, the development of RTP 2D OIHP-based photomemory has not been explored yet. In this work, the spatially addressable RTP 2D OIHPs-based nonvolatile flash photomemory is first investigated to explore the function of triplet excitons in elevating the performance of photomemory. Thanks to the triplet excitons generated in RTP 2D OIHP, extremely low photo-programming time of 0.7 ms, multilevel behavior of minimum 7 bits (128 levels), remarkable photoresponsivity of 19.10 AW-1 and significantly low power consumption of 6.79 × 10-8 J per bit can be achieved. The current study provides a new prospective in understanding triplet excitons function in nonvolatile photomemory.

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Microsystems play an important role in the Internet of Things (IoT). In many unattended IoT applications, microsystems with small size, lightweight, and long life are urgently needed to achieve covert, large-scale, and long-term distribution for target detection and recognition. This paper presents for the first time a low-power, long-life microsystem that integrates self-power supply, event wake-up, continuous vibration sensing, and target recognition. The microsystem is mainly used for unattended long-term target perception and recognition. A composite energy source of solar energy and battery is designed to achieve self-powering. The microsystem's sensing module, circuit module, signal processing module, and transceiver module are optimized to further realize the small size and low-power consumption. A low-computational recognition algorithm based on support vector machine learning is designed and ported into the microsystem. Taking the pedestrian, wheeled vehicle, and tracked vehicle as targets, the proposed microsystem of 15 cm3 and 35 g successfully realizes target recognitions both indoors and outdoors with an accuracy rate of over 84% and 65%, respectively. Self-powering of the microsystem is up to 22.7 mW under the midday sunlight, and 11 min self-powering can maintain 24 h operation of the microsystem in sleep mode.

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An overview of the electric field mill sensor specifications in applications related to the measurement of the atmospheric electric field was conducted. The different design approaches of the field mill sensor interface are presented and analyzed, while the sensitivity-related parameters of a field mill are discussed. The design of a non-complex analog sensor interface that can be employed for the measurement of the electric field in both fair and foul weather conditions, such as thunderstorms, is implemented using discrete components for experimental validation and is optimized in an integrated version in terms of noise and power consumption. Advanced noise simulations are conducted in a 180 nm CMOS process (XH018 XFAB). The energy-autonomous operation of the sensor for extended periods of time is made feasible due to the low power consumption of the front-end circuitry (165 µW at 3 V) as well as the proposed intermittent style of operation of the motor. The total sensing system is low power, and its realization is simple and cost-effective, while also offering adequate sensitivity (45 mV/kV/m), making it comparable to the existing works.

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The advancement of self-powered intelligent strain systems for human-computer interaction is crucial toward wearable and energy-saving applications. Simultaneously, lowering operating voltage and thus reducing power consumption are of particular interests. A brain-like smart synaptic hardware system is considered as a promising candidate for low-power, parallel computing and learning processes. However, the combination of low-voltage organic transistors and energy efficient smart synapse hardware systems driven by a tactile signal has been hindered by the limited materials and technology. Here, by employing an elastomeric copolymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) with a high HFP content of 25 mol %, flexible, low-voltage transistors (|VG| ≤ 3 V) and a low energy consumption synapse ≤ 9.2 × 10-17 J are devised simultaneously, along with the lowest quality factor (R = Pw × VG, 2.76 × 10-16 J V). Furthermore, based on the low voltage and low power consumption characteristics, flexible artificial tactile recognition system and Morse code recognition are established without any computing supporting. Mechanical flexibility, cycling stability, image contrast enhancement functions, and simulated pattern recognition accuracy of the multilayer perceptron neural network are also simulated. This work recommends a route of exploiting low voltage, low power consumption synaptic systems and smart human-machine interfaces with low energy loss based on flexible organic synaptic transistors.

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The simple structure and operation method of resistive random-access memory (RRAM) has attracted attention as next-generation memory. However, as it is greatly influenced by the movement of oxygen atoms during switching, it is essential to minimize the damage and adjust the defects. Here, we fabricated an ITO/SnOX/TaN device and investigated the performance improvement with the treatment of O2 plasma. Firstly, the change in the forming curve was noticeable, and the defect adjustment was carried out effectively. By comparing the I-V curves, it was confirmed that the resistance increased and the current was successfully suppressed, making it suitable for use as a low-power consumption device. Retention of more than 104 s at room temperature was measured, and an endurance of 200 cycles was performed. The filaments' configuration was revealed through the depth profile of X-ray photoelectron spectroscopy (XPS) and modeled to be visually observed. The work with plasma treatment provides a variety of applications to the neuromorphic system that require a low-current level.