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Voltage-controlled room temperature isothermal reversible spin crossover switching of [Fe{H 2 B(pz) 2 } 2 (bipy)] thin films is demonstrated. This isothermal switching is evident in thin film bilayer structures where the molecular spin crossover film is adjacent to a molecular ferroelectric. The adjacent molecular ferroelectric, either polyvinylidene fluoride hexafluoropropylene or croconic acid (C 5 H 2 O 5 ), appears to lock the spin crossover [Fe{H 2 B(pz) 2 } 2 (bipy)] molecular complex largely in the low or high spin state depending on the direction of ferroelectric polarization. In both a planar two terminal diode structure and a transistor structure, the voltage controlled isothermal reversible spin crossover switching of [Fe{H 2 B(pz) 2 } 2 (bipy)] is accompanied by a resistance change and is seen to be nonvolatile, i.e., retained in the absence of an applied electric field. The result appears general, as the voltage controlled nonvolatile switching can be made to work with two different molecular ferroelectrics: croconic acid and polyvinylidene fluoride hexafluoropropylene.

Ferroelectric field effect transistors (Fe-FETs) offer promising candidates for neuromorphic computing. However, it is still challenging to achieve a light-tunable field effect, which limits the function of photo-synapse. In this work, a ferroelectric semiconductor floating-gate transistor (FSF-FET) is proposed based on MoS2/h-BN/α-In2Se3 van der Waals heterojunctions (vdWHs), in which the two-dimensional ferroelectric semiconducting α-In2Se3 and dielectric h-BN serve as the trapped layer of charges and prevent layer, respectively. The excellent memory performances are exhibited, including a high programming/erasing ratio of over 107, a large memory window ratio of 74.69%, and good non-volatility. Moreover, the FSF-FETs also possess the light-tunable synapse behaviors, including the high paired-pulse facilitation of 236% and an obvious transition from short-term plasticity to long-term plasticity. The high recognition rate of 93.9% is achieved with dual-mode modulation of light and electrical pulses. The ferroelectric semiconductor floating-gate design opens up a strategy to realize the light-tunable field effect of Fe-FETs for photo-synapse. [ABSTRACT FROM AUTHOR]

This paper reports an all-optical vector magnetometer enhanced by a machine learning model. Using a dual probing beam setup, spin projections in both probe directions are simultaneously detected. Vector information is directly obtained from the measured phases of spin projection signals. To enhance the measurement accuracy and mitigate the dead zone effect, we introduce an artificial neural network (ANN) to link the phase signals to the field direction. With the addition of amplitude information to the ANN input, the average angle error is reduced to less than 0.3 ° within a hemisphere. Furthermore, this configuration demonstrates a field angle sensitivity of better than 30 μ rad / Hz 1 / 2 . [ABSTRACT FROM AUTHOR]

We report on a cascade nanosecond CdSe optical parametric oscillator with an output energy of 0.54 mJ at 100 Hz, temperature tuning within 9245–9285 nm, and a narrow (∼6 cm−1) spectral width achieved by a volume Bragg grating acting on the first stage. The CdSe crystal is pumped intracavity by the signal wave from the PPKTP-based first stage, and both stages operate under noncritical phase-matching conditions. The simple, compact, and robust setup produced the highest overall conversion efficiency for an all-solid-state laser system based on CdSe with 1-μm pumping, and the corresponding quantum conversion efficiency exceeded 13%. [ABSTRACT FROM AUTHOR]

Single-Event Burnout (SEB) can cause hard damage to devices, leading to permanent failure. However, previous studies have rarely explored the effects of high-energy proton irradiation-induced SEB in β-Ga2O3 Schottky Barrier Diode (SBD), and the underlying mechanisms remain largely unexplored. Experimental results indicate that the reverse bias voltage during irradiation is a critical factor influencing the failure of β-Ga2O3 SBD. Compared to 300 MeV proton irradiation without bias, the introduction of a 300 V reverse bias voltage results in a significant reduction in forward current density (JF). When the reverse bias voltage reaches 400 V or higher, the 300 MeV proton induces SEB in the device. The SEM image of the damaged region reveals that the irradiated device has "voids" formed due to the melting of the Ga2O3 material. Geant 4 and TCAD simulation results indicate that the burnout phenomenon is caused by the elevated lattice temperature inside the device, which results from the implantation of secondary particles under a high reverse bias voltage. As the reverse bias voltage increases, the maximum lattice temperature of β-Ga2O3 SBD also rises. When the reverse bias voltage is sufficiently high, the local lattice temperature inside the device reaches the melting point of Ga2O3 material, ultimately leading to SEB. [ABSTRACT FROM AUTHOR]

Phase transitions in metastable α-, κ(ε)-, and γ-Ga2O3 films to thermodynamically stable β-Ga2O3 during annealing in air, N2, and vacuum have been systematically investigated via in situ high-temperature x-ray diffraction (HT-XRD) and scanning electron microscopy (SEM). These respective polymorphs exhibited thermal stability to ∼471–525 °C, ∼773–825 °C, and ∼490–575 °C before transforming into β-Ga2O3, across all tested ambient conditions. Particular crystallographic orientation relationships were observed before and after the phase transitions, i.e., (0001) α-Ga2O3 → ( 2 ¯ 01) β-Ga2O3, (001) κ(ε)-Ga2O3 → (310) and ( 2 ¯ 01) β-Ga2O3, and (100) γ-Ga2O3 → (100) β-Ga2O3. The phase transition of α-Ga2O3 to β-Ga2O3 resulted in catastrophic damage to the film and upheaval of the surface. The respective primary and possibly secondary causes of this damage are the +8.6% volume expansion and the dual displacive and reconstructive transformations that occur during this transition. The κ(ε)- and γ-Ga2O3 films converted to β-Ga2O3 via singular reconstructive transformations with small changes in volume and unchanged surface microstructures. [ABSTRACT FROM AUTHOR]

Viscosity measurement is crucial in biomedical research and clinical diagnosis. Currently, rapid and non-contact methods for measuring viscosity remain challenging. We propose a method based on optical coherence tomography for fast, remote assessment of the liquid viscosity. The viscosity of the liquid sample was quantified according to Poiseuille's law, the flow velocity was determined using optical coherence tomography, and the real-time pressure difference was measured by two manometers. Glycerol–water mixtures with various viscosities were tested to assess the accuracy of the optical coherence tomography (OCT) viscosity measurement. Then, blood samples with different levels of hemodilution and hematocrit were measured to validate the feasibility of the OCT method in the blood viscosity measurement. The results indicate that the proposed method can provide rapid, non-contact liquid viscosity measurement. It could significantly impact research on hemodynamics and diagnosis of blood disorders. [ABSTRACT FROM AUTHOR]

Inspired by the human brain's capacity as a powerful biological computer capable of simultaneously processing a vast array of cognitive tasks, many emerging artificial synapse devices have been developed in recent years. Electric-double-layer (EDL) transistors based on interfacial ion-modulation have attracted widespread attention for simulating synaptic plasticity and neural functions. Here, low-voltage EDL p-type thin-film transistors (TFTs) are fabricated on glass substrates, with Ni-doped cuprous iodide (Ni0.06Cu0.94I) as the channel and chitosan as the dielectric. The electrical performance of the Ni0.06Cu0.94I TFTs is investigated: current on/off ratio of 6.4 × 104, subthreshold swing of 33 mV/dec, threshold voltage of 1.38 V, operating voltage of 2 V, and saturation field-effect mobility of 15.75 cm2 V−1 s−1. A dual in-plane gate OR logic operation is demonstrated. Importantly, by applying single voltage pulses, dual voltage pulses, and multiple voltage pulses to the gate, the Ni0.06Cu0.94I transistors exhibited typical synaptic characteristics, including short-term potentiation, short-term depression, long-term potentiation, long-term depression, paired-pulse facilitation, and spiking-rate-dependent plasticity. Furthermore, the synaptic transistor can also simulate the learning–forgetting–relearning process of the human brain. These remarkable behaviors of voltage-stimulated synaptic transistors have potential for neuromorphic applications in future artificial systems. [ABSTRACT FROM AUTHOR]

The development of flexible photodetectors is crucial for advancing wearable electronics and optoelectronic systems, but it faces significant challenges, such as maintaining high performance under mechanical strain and achieving cost-effective fabrication. Here, we fabricated a photodetector using poly(N-vinylcarbazole) (PVK) microwire arrays through a template-assisted method. The resulting devices exhibit high responsivity and exceptional mechanical flexibility, with the ability to maintain their photoelectric properties even when bent up to 150°. The photodetector exhibits high responsivity of 0.9 A W−1 and detectivity of 1.6 × 1010 Jones. This study demonstrates the potential of PVK microwire arrays for imaging applications, highlighting their suitability for integration into flexible and wearable devices. [ABSTRACT FROM AUTHOR]

Due to their unique compositional, structural, and morphological characteristics, hydrogen bonded two-dimensional (2D) layered materials and their one-dimensional tubular derivatives are endowed with great importance in the fields of both fundamental sciences and potential applications. In this work, γ-AlOOH nanotubes have been synthesized via a template-free one-step solvothermal alcoholysis method. The pressure response of the samples under static compression is investigated by in situ high-pressure angle dispersive synchrotron x-ray diffraction techniques. The results indicate that the compression behavior of nanotubes is different from those of its counterparts in the bulk and the nanoflake form. At pressures below 9.4 GPa, the unit-cell parameters a, b, and c decrease monotonously with pressure. In the pressure range of 10.6–19.9 GPa, an unexpected negative linear compressibility along the c-axis is observed experimentally in the compression behavior. When the high pressure is gradually released, it is evidenced that the compression of the prepared γ-AlOOH nanotubes is irreversible. The observed abnormal compression behavior and the unexpected negative linear compressibility may be explained by inflation associated with incorporation of the pressure transmitting medium within the interior cavity of the tubular nanostructures. Such a counter-intuitive phenomenon may find potential applications under high pressures. [ABSTRACT FROM AUTHOR]

We investigate the strong correlation between magnon–magnon coupling (M–M coupling) and coherent spin pumping in yttrium iron garnet/permalloy (Y3Fe5O12, YIG/Py) heterostructure through spin-torque ferromagnetic resonance technique. We demonstrate experimentally that the spin pumping of hybrid modes is the strongest near the coupling region at 295 K, indicating that coherent spin pumping is closely associated with magnon hybridization. Meanwhile, the coupling strength gc increases from 0.26 to 0.37 GHz with temperature reduction from 295 to 260 K, which is attributed to the enhancement of spin pumping, especially the hybrid mode characterized by spin pumping out of Py that provides a pronounced contribution. Furthermore, the increased linewidth of the hybrid mode near the coupling region at low temperatures leads to enhanced spin mixing conductivity. This enhancement, in turn, improves spin pumping. Our experiments discuss the underlying mechanisms that influence coupling strength in detail, providing deeper insights into tuning M–M coupling. [ABSTRACT FROM AUTHOR]

Water oxidation of photosynthesis at the oxygen evolving complex (OEC) is driven by the polarization field induced by the photoelectric hole. By highlighting the role of the polarization field in reshaping the spin and orbit potentials, we reveal in this work the characteristics and underlying mechanism in the relatively simpler OEC evolutions within the states S 0 – S 2 prior to the water oxidation. The characteristic shifts of the density of states (DOS) of the electron donor Mn atom are observed in the vicinity of the Fermi surface to occur with the spin flips of Mn atoms and the change in the Mn oxidation states during the electron transfer. Notably, the spin flips of Mn atoms point to the resulting spin configuration of the next states. It is found that the electron transfer tends to stabilize the catalyst OEC itself, whereas the proton transfer pushes the evolution forward by preparing a new electron donor, demonstrating the proton-coupled electron transfer. Meanwhile, it shows that the Mn–O bonds around the candidate Mn atom of the electron donor undergo characteristic changes in the bond lengths during the electron transfer. These concomitant phenomena uncovered in first-principle calculations characterize the essential equilibrium of the OEC between the state evolution and stability that forms the groundwork of the dynamic OEC cycles. In particular, the characteristic undulation of the DOS around the Fermi level occurring at the proton-coupled electron transfer can be used to reveal crucial processes in a wide range of realistic systems. [ABSTRACT FROM AUTHOR]

The basic unit of information in conductive bridge random access memory based on the redox mechanism of metal ions is physically stored in a conductive filament (CF). Therefore, the overall performance of the device is indissolubly related to the properties of such CFs, as unreliable performance often originates from unstable CFs behavior. However, accurately controlling the dissolution of CFs during device operation can be challenging due to their non-uniformity. This paper proposes a type of memristor based on a solid polymer electrolyte with a polyvinylpyrrolidone/polyvinyl alcohol composite layer structure. The properties of the composite layer are employed to regulate the number of CFs and the growth/fracture location, while the damage to the device by Joule heat is prevented. The device exhibits low operating voltage (0.5 V), stable switching conditions (2000 cycles), and a long holdup time (>3 × 104 s). [ABSTRACT FROM AUTHOR]

The synaptic response of ZnO/HfZrO memristor devices to electrical stimuli was studied. It was found that the frequency of the stimuli affects the rate of current increase, which can be explained by the cluster state of oxygen vacancies at the interface of ZnO/HfZrO. This variation in the synaptic response due to stimulus frequency was consistent with the dynamic adjustment of tolerance thresholds observed in the human brain's response to environmental stimuli. The rate of change in current, representing the sensitivity to stimuli, mirrors the biological nervous system's reaction to environmental changes, such as Ebbinghaus forgetting behavior. Additionally, frequent irregular changes in stimuli lead to a reduced lifespan of the devices, highly resembling the biological lifetime-injure on frequent environmental fluctuations. These findings highlight the memristors' significant similarity to biological nerves in response to stimuli, confirming their tremendous potential in bionic synaptic simulation applications. [ABSTRACT FROM AUTHOR]

We report the observation and theoretical analysis of photothermal phase modulation in an optical nanofiber (NF) immersed in light-absorbing gas. The phase modulation arises from the contrasting photothermal processes experienced by the mode field within and outside the NF, which exhibits significant wavelength and pressure dependence in the nanoscale waveguides. By designing the diameter of the NF, the photothermal phase modulation can be readily controlled, and a nullification of phase modulation is achieved at a specific wavelength. Experiments on NFs with different diameters demonstrated pressure-controllable phase modulation up to 0.058π rad/mW, potentially allowing the development of nanoscale all-optical modulators and sensors with optimal performance. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate the Anderson localization effect in coupled metamaterial structures. We introduce the random variables by randomly choosing the geometrical parameter of structures and randomly choosing the distance between structures to reduce the coupling of metamaterial and this decoupling effect is equivalent to Anderson localization effect, which can reduce the coupling without enlarging the area of unit cell. We demonstrate our idea by employing the experiments. Furthermore, we present an example of deflector to see how this decoupling effect can help us design functional devices. [ABSTRACT FROM AUTHOR]

From spintronics to data storage technology, two-dimensional (2D) ferromagnetic materials show great promise for various applications. This work reports a series of stable ferromagnetic transition metal boride FenB2+2n (n = 1, 2), where robust long-range ferromagnetic exchange coupling and large perpendicular magnetic anisotropy energy (MAE) allow the ferromagnetic transition temperature (Tc) of the FenB2+2n monolayer to reach above room temperature. The metallic FenB2+2n exhibits n- and p-type Dirac transport in both spin channels with a high Fermi velocity. Furthermore, the application of biaxial compressive strain and electron doping can greatly increase the ferromagnetic coupling and MAE of FeB4 monolayers. On this basis, the FeB2C2 alloy with a high concentration of carbon substitution has been designed, which allows the nonvolatile integration of in-plane compressive strain and electron doping. As expected, this substitution doping resulted in a significant increase in the Tc and MAE of the system. Our findings provide perspectives for the study of 2D magnetic materials. [ABSTRACT FROM AUTHOR]

Negative charge card refrigeration, as a new solid-state refrigeration technology, has garnered much interest with its broad application potential in the area of temperature control for sensors and electronic devices. In this study, antiferroelectric thin films of Pb1−xMnxZrO3 (x = 0.0%, 0.5%, 1.0%, 2.0%, abbreviated as PMZ-100x) were prepared on tin oxide doped with fluorine/glass substrates by the sol-gel method. When the variable temperature P–E loops under various applied electric fields are compared, the P–E loops gradually change from linear to typical double P–E loops. This result implies that temperature and electric field work together to induce the phase change. The negative electrocaloric effect of the PMZ-0.5 film is greatly enhanced at 50 °C, 444 kV/cm, ΔS = 16.75 J·K−1·kg−1, ΔT = −16.39 K, in comparison to the PbZrO3 film (ΔS = 11.84 J·K−1·kg−1, ΔT = −12.48 K at 75 °C, 421 kV/cm). The great cooling performance indicates that PMZ-100x films have excellent potential for use in integrated circuit solid-state cooling. [ABSTRACT FROM AUTHOR]

Electrowetting liquid lenses have aroused considerable interest among researchers in a variety of industrial applications and wetting sciences. However, conventional electrowetting liquid lenses face significant limitations in their optical power tuning range due to contact angle saturation. To address this issue, our research introduces a polyelectrolyte mixture (PM) composed of ammonium polyphosphate and potassium chloride, which enables a broad optical power tuning range for electrowetting liquid lenses. Through a comprehensive analysis involving viscosity, Raman spectrum, and contact angle measurements, we offer additional insights into the interdisciplinary mechanism of the PM in enhancing the electrowetting effect. Our investigation elucidates how the conformation of the polyelectrolyte and the formation of hydrogen bonds at varying concentrations can impact the electrowetting gain. By optimizing the electrowetting concentration of the PM (12.5 wt. % ammonium polyphosphate and 7.5 wt. % potassium chloride), we achieve a liquid lens with an extensive tuning range (−37.97 to +18.71 D) at 0–45 V, featuring a substantial aperture (6.4 mm) and a low threshold voltage (10 V). This PM formulation effectively mitigates contact angle saturation, thereby offering promising applications and paving the way for the development of liquid lenses with a significantly enhanced optical power tuning capacity. [ABSTRACT FROM AUTHOR]

This study presents an unprecedented directional transport phenomenon during the coalescence of two droplets on a pre-wetted cylindrical fiber, where the larger droplet is pulled toward the smaller one. The magnitude of this effect often exceeds the gravitational pull, enabling coalescing droplets to climb up a vertical fiber. This occurs primarily because the viscous friction that the droplets experience is negatively correlated with the droplet size. We present a scaling relation and a mass-spring-damper model to explain the phenomenon, which shows good agreement with the experimental results. This research reveals an intriguing aspect of the coalescence dynamics of droplets on a pre-wetted fiber, offering a fresh perspective on the interfacial phenomena in droplet–fiber systems. [ABSTRACT FROM AUTHOR]

Ammonium (NH4+) ion aqueous supercapacitors have gained significant attention due to their notable cost-effectiveness, safety profile, and environmental benefits. Despite this, the optimization of the capacitive performance of electrode materials for NH4+ ion storage remains inadequate. To tackle these challenges, we present a composite electrode depend upon molybdenum disulfide (MoS2) and indium tin oxide nanowires (MoS2@ITO NWs) as the primary host for (NH4+) ions. Additionally, we introduce a straightforward radio frequency nitrogen (N) plasma technique to incorporate nitrogen doping into the MoS2 film, thereby enhancing its performance. The introduction of N plasma doping into two-dimensional MoS2 results in an expansion of the interlayer distance and an improvement in electronic conductivity. This, in turn, facilitates the facile and highly reversible insertion and extraction of NH4+ ions during cycling. Consequently, the N plasma doping significantly enhances the device areal capacitance of MoS2@ITO NWs, increasing it from 78.6 to 161.8 mF cm−2 at 1 mA cm−2, with an exceptional capacity retention (>89.2% after 10 000 cycles) and superior rate capability up to 10 mA cm−2. The integration N of atoms within the straightforward hierarchical core–shell design strategy exhibits promising prospects for bolstering the performance of metal sulfide electrodes and other high-capacity electrode materials aimed at energy storage applications. [ABSTRACT FROM AUTHOR]

To alleviate high costs and lengthy trial-and-error periods associated with traditional optimization methods for perovskite solar cells (PSCs), we developed a data-driven reverse design framework for high-efficiency PSCs. This framework integrates machine learning and Bayesian optimization (BO) to accelerate the optimization process of PSCs by intelligently recommending the most promising parameter configurations for PSCs, such as device structure and fabrication processes. To improve the robustness of the framework, we first designed a two-stage sampling strategy to alleviate the issue of imbalanced dataset classes. Subsequently, by integrating "experimental knowledge constraints" into the BO process, we achieved precise parameter configurations, thus avoiding discrepancies between predicted and actual results due to parameter mismatches. Finally, using SHapley Additive exPlanations, we unveiled key factors influencing the power conversion efficiency (PCE), such as the composition of perovskite solvents. Our framework not only precisely predicted the PCE of PSCs with an area under the curve of 0.861 but also identified the optimal parameter configurations, achieving a high probability of 0.981. This framework offers substantial support for minimizing redundant experiments and characterizations, effectively accelerating the optimization process of PSCs. [ABSTRACT FROM AUTHOR]

Materials exhibiting caloric effects can serve as green alternatives in place of the gas refrigerants used in traditional vapor refrigeration systems, which are facing rising energy usage and environmental issues. This study investigates the barocaloric effect of fatty acids, which are typical phase-change materials. Fatty acids exhibit a reversible isothermal entropy change of about 600 J kg−1 K−1 and an adiabatic temperature change of about 10 K at a pressure less than 60 MPa, resulting from the pressure-driven liquid–solid phase transition. In the solid state, the adiabatic temperature change of fatty acids is larger than that of the n-alkanes with similar transition temperatures. Raman analysis indicates that the population of the distorted molecular chains in fatty acids is remarkably decreased when they are transformed from liquid to solid state, leading to the colossal entropy change. For solid fatty acids, the intermolecular interactions characterized by the hydrogen bonds are significantly strengthened under pressure, which explains their large adiabatic temperature change. This study suggests fatty acids are promising refrigerants for eco-friendly barocaloric cooling. [ABSTRACT FROM AUTHOR]

In this article, SnxCu1−xI thin-film transistors were fabricated on a glass substrate, with CuI doped with varying concentrations of SnI2 serving as the channel and chitosan as the dielectric. When x = 0.06, the device exhibited optimal performance: a current on/off ratio of 2.56 × 105, a subthreshold slope of 31.67 mV/dec, a threshold voltage of 1.33 V, and a saturated field-effect mobility of 21.75 cm2 V−1 s−1. Due to the electric double layer effect of chitosan, the operating voltage of the devices was reduced to below 2 V. Simulations were also conducted on the behavior and functionality of artificial synapses, such as short-term plasticity, long-term plasticity, and paired-pulse facilitation. Building upon the functionalities of artificial synapses, the Sn0.06Cu0.94I neuromorphic transistors simulated the fundamental pain perception function of biological nociceptors. Finally, the effects of bias stress and laser irradiation on the devices were investigated, indicating the excellent stability of the Sn0.06Cu0.94I neuromorphic transistors. Fabricated via the solution process, this low-voltage neuromorphic transistors hold significant implications for applications in bionic sensing systems and neuromorphic chip technology. [ABSTRACT FROM AUTHOR]

Here, we demonstrate a strategy for the quantification of electron–phonon interaction (EPI) of bismuth telluride (Bi2Te3) under hydrostatic pressure through systematic femtosecond pump-probe spectroscopy. Two optical phonon modes, namely A 1 g and Eg with frequencies of 1.87 and 3.71 THz at ambient pressure, are detected using time-resolved transient reflection (TR) measurement. Frequencies of both coherent phonon oscillations increase monotonically by around 33% and 17%, respectively, with the rising pressure up to 5.67 GPa, indicating pressure-induced phonon-hardening effect. The mode-specific electron–phonon coupling constant λ of Bi2Te3 under different pressures are calculated with the frequency of the A 1 g mode. It turns out that the variation of phonon lifetime and the corresponding phonon dephasing rate of the A 1 g mode may result from the pressure modification of λ. Our findings reveal the significant role of EPI in phonon transport and shed light on further manipulation on thermoelectric efficiency of Bi2Te3 with external strain. [ABSTRACT FROM AUTHOR]

This work demonstrates a high-performance monolithically integrated GaN inverters platform, which incorporates enhancement-mode (E-mode) and depletion-mode (D-mode) GaN high-electron-mobility transistors (HEMTs) simultaneously using an Al:HfOx-based charge trapping layer. The developed E-mode HEMT exhibits a positive threshold voltage of 2.6 V, a high ON–OFF current ratio of 1.9 × 108, a current density of 376 mA/mm, and an ON-resistance of 15.31 Ω·mm. Moreover, the direct-coupled field-effect-transistor logic (DCFL) GaN inverter was characterized with and without D-mode device threshold voltage (VTH) modulation, demonstrating improved output swing and switching threshold shift by proposed VTH modulation. The optimized DCFL GaN inverter manifests a switching threshold of 2.34 V, a logic voltage output swing of 4.98 V, and substantial logic-low and logic-high noise margins of 2.16 and 2.49 V, respectively, at a supply voltage of 5 V. These results present a promising approach toward realizing monolithically integrated GaN logic circuits for power IC applications. [ABSTRACT FROM AUTHOR]

We experimentally demonstrated that composites, being effective in optimizing the thermoelectric performance, can also enhance photothermoelectric effects in this work. In detail, we employed an alternating-growth in chemical-vapor-transport to grow the SnSe–SnSe2 composite crystals. The photo-responsivities of SnSe–SnSe2 (atomic-weight-ratio as 44%–56%) composite are comparable to SnSe crystals in the visible band (444 and 532 nm). However, the responsivities of SnSe–SnSe2 have remarkable 27.3% enhancement than those of SnSe crystal at the near-infrared band (1310 and 1550 nm). Supported by optical spectroscopy and theoretical electronic band structure, the enhanced optical responsivity of SnSe–SnSe2 composites is due to the formation of P–N junctions at interfaces between SnSe and SnSe2, leading to more optical transition channels and corresponding optical absorptions in near-infrared band. Our work verifies that hetero-junction formed among constituent compounds in composites is effective in optimizing the photothermoelectric response of thermoelectric materials in certain electromagnetic bands, paving the way to develop photoelectric detection devices. [ABSTRACT FROM AUTHOR]

Searching the optimal doping compositions of the Y-type hexaferrite Ba2Mg2Fe12O22 remains a long-standing challenge for enhanced non-collinear magnetic transition temperature (TNC). Instead of the conventional trial-and-error approach, the composition-property descriptor is established via a data driven machine learning method named sure independence screening and sparsifying operator. Based on the chosen efficient and physically interpretable descriptor, a series of Y-type hexaferrite compositions are predicted to hold high TNC, among which the BaSrMg0.28Co1.72Fe10Al2O22 is then experimentally validated. Test results indicate that, under appropriate external magnetic field conditions, the TNC of this composition reaches up to 568 K, and its magnetic transition temperature is also elevated to 735 K. This work offers a machine learning-based route to develop room temperature single phase multiferroics for device applications. [ABSTRACT FROM AUTHOR]

The LiNbO3 (LNO) single crystal receives wide applications in nonvolatile memories, surface acoustic wave devices, and electro-optic modulators. However, engineering of antiparallel domain patterns within micrometer-sized devices generally requires a poling voltage more than a few thousands of volts. The high poling voltage could invoke dielectric breakdown. Here, we found an effective method to increase the local electric field significantly for domain nucleation at the interfaces of an etched LNO mesa in contact to two concave side electrodes, while the electric field across the protruding intra-electrode area can be lower by 10 times after the metal diffusion at the surface. Subsequent piezoresponse force microscopy mapping shows the nucleating domains to grow up through the entire intra-electrode area. This method is universal and analogous to other ferroelectric devices for the realization of low-voltage operations. [ABSTRACT FROM AUTHOR]