Publisher：Nano Research  

Boron arsenide, renowned for its ambipolar charge mobility and superior thermal conductivity, has emerged as a focal point of contemporary research. Despite its promising properties, the impact of water on the electronic conductivity (EC) of boron arsenide remains largely unexplored. In this study, we synthesized amorphous boron arsenide (a-BAs) nanosheets through an innovative in situ reaction involving elemental arsenic and sodium borohydride within a low-pressure, hydrogen-rich environment. We performed both theoretical and experimental analyses to investigate the influence of water on EC in representative a-BAs. These nanosheets were integrated into self-powered, flexible humidity sensors, demonstrating a substantial current change across nearly five orders of magnitude and achieving an extraordinary response of 8.4 × 10⁶% at 85% RH without an additional power unit. The sensors exhibited a remarkable linear correlation between the logarithmic response function and a wideranging detection capability (11%–97% RH), achieving an extraordinary response of 1.4 × 10⁶% at 97% RH under a 1 V bias. This research not only introduces a straightforward synthesis method for amorphous boron arsenide nanosheets but also highlights the significant impact of water on the EC of boron arsenide, paving the way for developing self-powered highperformance sensing materials.

DOI： 10.26599/NR.2026.94908321

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Scopus

Language：English   Publisher：Light Science and Applications  

Current crystalline thin-film production techniques typically require specific growth substrates, posing significant challenges for their use in flexible electronics and integrated optoelectronics. In response to these challenges, we introduce a novel method called ‘induced fit growth’, inspired by the induced fit theory in molecular biology. This method overcomes the limitations of current techniques by enabling the deposition of Ga-based semiconductor films, including GaSb, GaSe, GaAs, and GaAsSb, with controllable thickness and morphology on arbitrary substrates. Utilizing a low-cost, wafer-scale vapor deposition process compatible with standard semiconductor procedures, these Ga-based films can be patterned for various functional applications. For example, the patterned Ga-based thin films exhibit broad applicability in p-channel transistor arrays (with hole mobility of 0.25 cm² V⁻¹ s⁻¹), functional synaptic devices, and flexible omnidirectional imaging sensors (maintaining functionality at incident angles as low as 5°). Overall, the proposed induced fit growth method facilitates the growth of Ga-based semiconductor films with greater integration flexibility, enhancing their advanced functionality and broad applicability.

DOI： 10.1038/s41377-025-02096-2

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PubMed

Language：English   Publisher：Angewandte Chemie International Edition  

Microenvironment modulation, involving the selective adsorption of ions and the engineering of hydrogen radicals, is critical for the neutral electrochemical reduction of nitrate to ammonia at high current densities. In this work, self-adaptive low-valent indium single atoms SAs decorated copper-based nanosheets were investigated as a prototype. The catalyst exhibits a maximum ammonia Faradaic efficiency (FE<inf>NH3</inf>) of 99.36% and a high NH<inf>3</inf> yield rate of 29.02 mg h⁻¹ mg<inf>cat.</inf>⁻¹ in neutral electrolyte. In-depth experiments and theoretical calculations suggest that the indium SAs optimize the local electronic distribution of the derived Cu matrix through strong p-d orbital couplings, with the electron-relay effect, thereby enhancing electron transfer and regulating the supply of hydrogen radicals to accelerate the hydrogenation process. Furthermore, in situ Raman results and molecular dynamics simulations reveal that the indium SAs can act as solid-state buffering sites by inducing a potential-dependent adsorption behavior of NO<inf>3</inf>⁻ over SO<inf>4</inf>²⁻ as a supporting oxoanion in the electric double layer, consequently maintaining high reaction activity and selectivity. Herein, the as-designed electrode operates stably at 200 mA cm⁻² for 150 h in a bipolar membrane electrode assembly electrolyzer with a FE<inf>NH3</inf> of ∼83%, indicating promising practical applications.

DOI： 10.1002/anie.202520730

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PubMed

Publisher：Applied Physics Letters  

The intrinsically weak optical absorption and limited photocarrier separation of atomically thin two-dimensional (2D) materials often limit the photodetector performance. Here, we report an in situ surface growth strategy for preparing a Bi<inf>2</inf>O<inf>2</inf>Se/Te heterojunction via a low-temperature chemical vapor deposition method. One-dimensional Te nanowires directly grow on 2D Bi<inf>2</inf>O<inf>2</inf>Se nanosheets, forming a clean van der Waals interface and enhancing optical absorption capacity. The Bi<inf>2</inf>O<inf>2</inf>Se/Te heterostructure exhibits excellent optoelectronic performance, including an enhanced photocurrent of 1.12μA, a high responsivity of 50A/W, and a fast response speed of 32/>168ms. The enhanced photocurrent and responsivity arise from the efficient electron injection from Te to Bi<inf>2</inf>O<inf>2</inf>Se, and hole trapping at the heterointerface. This work demonstrates a non-destructive approach for preparing high-quality heterojunctions and provides an effective pathway for next-generation high-performance near-infrared photodetectors.

DOI： 10.1063/5.0311580

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Scopus

Language：English   Publisher：Nature Communications  

Boron arsenide has recently attracted significant attention for its thermal and electronic properties. However, its lengthy growth process and bulk structure limit its application in advanced semiconductor systems. In this study, we introduce a method for synthesizing ultrathin crystalline hexagonal boron arsenide (h-BAs) nanosheets in large quantities via an in-situ chemical reaction of sodium borohydride with elemental arsenic in a low-pressure hydrogen atmosphere. We successfully fabricated h-BAs-based memory devices with ON/OFF current ratios up to 10⁹, low energy consumption of less than 4.65 pJ, and commendable stability. Furthermore, we have developed flexible h-BAs-based memristors with good stability and robustness. This research not only provides a promising avenue for synthesizing h-BAs nanosheets, but also underscores their potential in the development of next-generation electronic devices.

DOI： 10.1038/s41467-025-60038-3

Scopus

PubMed

Language：English   Publisher：International Exchange and Innovation Conference on Engineering & Sciences  

The distinctive superiority of CsPbBr_3/Cs_4PbBr_6 nanocomposite perovskite stability had directed the researchers to focus on exploring in-depth of its properties to meet the growing demand for achieving the optimal properties of perovskite for commercial applications. This review aspires to provide a concise summary addressing the most widely fabrication techniques of CsPbBr_3/Cs_4PbBr_6 nanocomposite perovskite with touching upon its optical features as well as its applications for a wide range of industrial and commercial sectors. We consider that this review offers a broad perspective of existing obstacles, references for diverse insights of nanocomposite perovskite production and discussion to improve its future usage for various applications.

DOI： 10.5109/7395636

Scopus

CiNii Research

Publisher：Chemistry Letters  

In this study, FeNi alloy/carbon composites were synthesized using the LiCl-KCl molten-salt-assisted method at different temperatures. Electrochemical tests demonstrate that FeNi/carbon synthesized at 1,000 °C exhibits the best oxygen evolution reaction performance, with an overpotential of 306.7 mV at a current density of 10 mA cm-2 and excellent long-term stability over 100 h. A series of characterizations reveals that the improved activity is attributed to the synergistic effects of the conductive and porous carbon framework, the well-grown FeNi alloy nanoparticles, and optimized surface electronic states that derive from the increasing calcination temperature.

DOI： 10.1093/chemle/upaf130

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Scopus

Publisher：Journal of Materials Chemistry A  

The growing need for cost-effective and efficient energy conversion technologies drives the development of advanced catalysts for the oxygen evolution reaction (OER). Our research focuses on high-entropy spinel oxides (HESOs) as efficient OER electrocatalysts. Using the molten salt synthesis (MSS) method, we prepared HESO nanoparticles from Fe, Ni, Co, Mn, and Zn. By adjusting the precursor ratios, we obtained equimolar (Ni0.2Fe0.2Co0.2Mn0.2Zn0.2)3O4, CoMn-rich, and NiFe-rich samples to examine compositional effects. Among these, the CoMn-rich HESO sample exhibited superior catalytic performance in 1 M KOH solution, with an overpotential of 330.1 mV at 10 mA cm−2 and a Tafel slope of 53.5 mV dec−1. Its promising long-term stability and enhanced reaction kinetics are significant. The synergistic effect of Co and Mn with high valence states and enhanced oxygen adsorption on the CoMn-rich HESO lower the energy barrier and accelerate electron transfer, improving the reaction kinetics. Density functional theory (DFT) calculations further reveal the relationship between orbital hybridization and catalytic performance, emphasizing the contribution of high valence metal active centers in improving performance. The density of states (DOS) analysis further demonstrates the stronger covalency between the 3d orbitals of the metal active site and the O 2p orbitals on the surface of CoMn-rich samples, which favors the absorption of oxygen species and thus improves the electrochemical performance. This work presents an effective method for HESO synthesis and opens new avenues for energy conversion research.

DOI： 10.1039/d4ta08485c

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Scopus

Publisher：Chemical Engineering Journal  

Flexible, highly sensitive strain sensors operating at small strains have shown significant potential in applications such as pulsebeat detection and sound signal acquisition. In this study, we introduce ultrasensitive piezoresistive strain sensors designed to function effectively at small strains using a Te nanomesh. A large-area Te nanomesh is deposited onto a flexible polyimide substrate through physical vapor deposition, facilitating the on-site fabrication of strain sensors. The unique mesh structure imparts exceptional sensitivity to strain, achieving a remarkable gauge factor of up to 9.93 × 108. By coating the strain sensors with a thin layer of polydimethylsiloxane, we significantly enhance their stability, with minimal degradation observed even after 1000 loading-releasing cycles. The performance of these strain sensors is contingent on the mesh's density, which can be precisely controlled by adjusting the growth time of the Te nanomesh. Furthermore, our strain sensor exhibits a rapid response time of less than 4 ms, indicating its swift responsiveness. To demonstrate the superior performance of these strain sensors, we showcase their efficacy in monitoring finger bending, ruler vibrations, and sphygmus. Our findings introduce a novel design concept for flexible strain sensors and represent a significant advancement in wearable electronics and human-machine interaction technologies.

DOI： 10.1016/j.cej.2025.162024

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Scopus

Language：English   Publisher：Nature Communications  

Maximizing metal-substrate interactions by self-reconstruction of coadjutant metastable phases can be a delicate strategy to obtain robust and efficient high-density single-atom catalysts. Here, we prepare high-density iridium atoms embedded ultrathin CoCeOOH nanosheets (CoCe-O-IrSA) by the electrochemistry-initiated synchronous evolution between metastable iridium intermediates and symmetry-breaking CoCe(OH)2 substrates. The CoCe-O-IrSA delivers an overpotential of 187 mV at 100 mA cm−2 and a steady lifespan of 1000 h at 500 mA cm−2 for oxygen evolution reaction. Furthermore, the CoCe-O-IrSA is applied as a robust anode in an anion-exchange-membrane water electrolysis cell for seawater splitting at 500 mA cm−2 for 150 h. Operando experimental and theoretical calculation results demonstrate that the reconstructed thermodynamically stable iridium single atoms act as highly active sites by regulating charge redistribution with strongly p-d-f orbital couplings, enabling electron transfer facilitated, the adsorption energies of intermediates optimized, and the surface reactivity of Co/Ce sites activated, leading to high oxygen evolution performance. These results open up an approach for engineering metastable phases to realize stable single-atom systems under ambient conditions toward efficient energy-conversion applications.

DOI： 10.1038/s41467-025-58163-0

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PubMed

Publisher：Advanced Functional Materials  

Van der Waals (vdWs) p–n junctions assembled from 2D materials offer enhanced flexibility for creating versatile electronic and optoelectronic devices, attracting significant interest. However, the lack of reliable methods to produce high-quality p-type 2D semiconductors, especially patterned p-type channels, remains a major challenge for progress in the field. Here, a precise substitutional doping strategy for 2D semiconductors is presented, enabling the production of millimeter-scale WS2 single-crystal thin films with tailored p-type and n-type properties. This advancement supports the fabrication of high-performance WS2-based p-type and n-type field-effect transistor (FET) miniaturized arrays with near-ohmic contact. Building on this progress, a WS2 van der Waals homojunction p-n array demonstrating distinct anti-ambipolar behavior and excellent rectification characteristics is developed. In self-powered photodetection mode, leveraging the strong coupling of the vdWs homojunction interface, the device achieves an exceptional photovoltaic effect with a high specific detectivity of 3.4 × 1010 Jones and a fast response time of 400 µs. The development of WS2 p-n homojunction arrays presents immense potential for advancing next-generation logic electronics and optoelectronic devices, opening new avenues for large-scale industrial applications.

DOI： 10.1002/adfm.202425884

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Scopus

Publisher：ACS Applied Energy Materials  

The growing need for energy conversion technologies has stimulated the development of innovative electrocatalysts designed explicitly for oxygen evolution reactions (OER). Nonprecious metal/carbon-based composites are widely studied for this purpose due to their low cost and unique structures. However, conventional methods for preparing transition metal/carbon composites are often cumbersome and time-consuming. These methods have other disadvantages, such as poor catalyst uniformity, limited potential for surface modification, and excessive oxidation of metal particles. In this work, we employed a simple one-step molten salt (MS) method to synthesize FeNi alloy/carbon composites. The sample prepared by the MS strategy, with an optimal Fe/Ni ratio, performs a low overpotential of 279.4 mV at a current density of 10 mA cm-2 and a small Tafel slope of 45.7 mV dec-1. Compared with the sample prepared through traditional pyrolysis, the sample prepared by the MS method demonstrates modulated and optimized surface characteristics for both the carbon support and metallic particles. Furthermore, the synthetic process enables the uniform growth of alloy particles on the carbon substrate. These structural improvements result in abundant defects and active sites, significantly enhancing OER activity. Overall, this work highlights the role of the MS method in promoting the catalytic activity of FeNi alloy/carbon composites. This research contributes to advancing non-noble metal electrocatalysts for future catalytic applications.

DOI： 10.1021/acsaem.4c02958

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Scopus

Language：English   Publisher：Advanced Materials  

Reconfigurable devices with field-effect transistor features and neuromorphic behaviors are promising for enhancing data processing capability and reducing power consumption in next-generation semiconductor platforms. However, commonly used 2D materials for reconfigurable devices require additional modulation terminals and suffer from complex and stringent operating rules to obtain specific functionalities. Here, a p-type disordered tellurium oxide is introduced that realizes dual-mode reconfigurability as a logic transistor and a neuromorphic device. Due to the disordered film surface, the enhanced adsorption of oxygen molecules and laser-induced desorption concurrently regulate the carrier concentration in the channel. The device exhibits high-performance p-type characteristics with a field-effect hole mobility of 10.02 cm2 V−1 s−1 and an Ion/Ioff ratio exceeding 106 in the transistor mode. As a neuromorphic device, the vision system exhibits biomimetic bee vision, explicitly responding to the blue-to-ultraviolet light. Finally, in-sensor denoising and invisible image recognition in static and dynamic scenarios are achieved.

DOI： 10.1002/adma.202412210

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Scopus

PubMed

Publisher：Advanced Functional Materials  

Dion–Jacobson-type 2D halide perovskites (DJPs) present an ideal alternative to their 3D counterparts due to their superior stability and exceptional optoelectronic properties. Despite the numerous DJPs proposed in recent years, the impact of different spacer cations on DJPs remains unclear. This understanding is crucial for researchers to select suitable materials and is an urgent requirement for the development of higher-performance DJPs-based devices. In this study, the influence of the chain-like spacer cations with varying branch chains and chain lengths is thoroughly examined using both theoretical and experimental methods. The findings reveal that spacer cations with high polarity components along the main chain direction enhance the stability and photoelectric properties of DJPs. Additionally, it is found that the chain length of the spacer cation plays a critical role. Chain lengths that are too long or too short can detrimentally affect the photoelectric performance and stability of DJPs. These insights will guide researchers in selecting suitable spacer cations and in innovating new types of DJPs.

DOI： 10.1002/adfm.202409987

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Scopus

Publisher：Chemical Engineering Journal  

Zn–CO2 batteries are attracting much attention because the CO2 reduction reaction (CO2RR) to hydrocarbon products takes place during the discharge process. However, the CO2RR products in Zn–CO2 batteries are almost exclusively C1 products (CO and HCOOH) without exploring high energy density products. Therefore, in this work, the functional polymers-coated Cu hollow microspheres are prepared as the cathodic catalysts in the primary Zn–CO2 batteries with the aim of obtaining the high energy density product of CH4. Functional polymers composed of polyethyleneimine (PEI) and perfluorinated sulfonic acid (PFSA) are orderly coated on the Cu hollow microspheres prepared by using the colloidal self-assembly technique to form a Cu/PEI/PFSA cathodic catalyst. According to the results of the finite element analysis, PFSA enables CO2 diffusion length to reach more than 200 nm, while the PEI gives rise to a high steady-state CO2 concentration of 0.726 mol m−3 on the Cu surface. Hence, as compared to the Cu nanoparticles and bare Cu hollow microspheres catalysts, the Cu/PEI/PFSA-based primary Zn–CO2 battery exhibits a maximum power density of 1.36 mW cm−2 and a high Faraday efficiency of 42.78 % towards CH4 at 5 sccm of CO2 flow rate and 1.25 mA cm−2 of current density. In addition, a homemade in-situ Raman device displays the evolution of the CO2RR intermediates during the operation of the primary Zn–CO2 batteries, revealing the direction of CO2 conversion to hydrocarbon products.

DOI： 10.1016/j.cej.2024.152856

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Scopus

Publisher：Materials Today Energy  

Ammonia, with its wide-ranging applications in global industries, plays an indispensable role in the growth and sustainability of modern society. Electrochemical nitrate reduction (eNO3RR) presents an environmentally friendly pathway for ammonia production, sidestepping the energy consumption and greenhouse gas emissions associated with the conventional Haber–Bosch process. However, developing efficient and selective catalysts for eNO3RR is challenging due to its intricate multiproton-coupled electron transfer process and the competing hydrogen evolution reaction. This review dives deep into the recent advancements in eNO3RR, shedding light on the mechanism through in situ spectroscopic studies and innovative strategies for catalyst design. We first lay out the possible reaction pathways and products in eNO3RR and then introduce a variety of in situ electrochemical characterizations that provide real-time insights into the reaction mechanism. We also explore strategies for rational electrocatalyst design to optimize the performance. Representative examples of advanced materials with high activity, selectivity, and stability are highlighted to underscore the progress made in this field. Finally, we outline emerging opportunities and future directions, such as developing multifunctional nanostructured catalysts through integrated computational and combinatorial approaches. This review aims to provide valuable insights and guidance for developing nitrate electroreduction and the efficient production of green ammonia in industry.

DOI： 10.1016/j.mtener.2024.101610

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Scopus

Language：English   Publisher：ACS Applied Materials and Interfaces  

Constructing a unipolar heterojunction is an effective energy band engineering strategy to improve the performance of photoelectric devices, which could suppress dark current and enhance detectivity by modulating the transfer of carriers. In this work, unipolar heterojunctions of Si/PbI2 and GaSb/PbI2 are constructed successfully for high-performance self-powered near-ultraviolet photodetection. Owing to the unique band offset of unipolar heterojunctions, the transport of holes is blocked, and only photogenerated electrons in PbI2 can flow unimpeded under the driving force of the built-in electric field. Thus, the recombination of photogenerated electron-hole pairs is suppressed, contributing to high-performance near-ultraviolet photodetection. The as-fabricated Si/PbI2 self-powered near-ultraviolet photodetector exhibits a low dark current of 10-13 A, a high Ilight/Idark ratio of 104, and fast response times of 26/24 ms, which are much better than those of the PbI2 metal-semiconductor-metal photodetector. Furthermore, the as-fabricated GaSb/PbI2 unipolar heterojunction photodetector also exhibits impressive self-powered near-ultraviolet photodetection behaviors. Evidently, this work shows the potential of unipolar heterojunctions for next-generation Si-based and GaSb-based high-performance photodetection.

DOI： 10.1021/acsami.4c07333

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Scopus

PubMed

Publisher：Chem Catalysis  

Competing hydrogen evolution reaction (HER) and sluggish multi-electron/proton-involved steps are the major obstacles to improving the efficiency and selectivity of electrochemical nitrate reduction to ammonia (eNO3RR). Herein, we modified Co3O4 nanoparticles with doped rare-earth La atoms and carboxylic (COO−)-based organic ligands. The COO− groups efficiently reduce the water activity around the active sites by forming hydrogen bonds, thus controlling proton accessibility and regulating the adsorption selectivity between nitrate ions and protons. Simultaneously, introducing oxygen vacancies through La doping establishes active sites with a strong affinity for nitrate ions and an electron-rich local environment conducive to eNO3RR. The electrocatalyst exhibits superior activity and selectivity with an ammonia Faradaic efficiency of up to 99.41% and a yield rate of 5.62 mg h−1 mgcat−1 at −0.3 V vs. reversible hydrogen electrode (RHE). Notably, the catalyst maintains over 90% Faradaic efficiency for NH3 production across a broad potential range of 400 mV, surpassing most recently reported eNO3RR electrocatalysts.

DOI： 10.1016/j.checat.2024.101024

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Scopus

Publisher：Advanced Functional Materials  

2D Ruddlesden─Popper (RP) halide perovskites are attracting increasing research interest due to their enhanced stability compared to 3D perovskites. However, the quantum confinement effect of bulk organic spacers hinders the separation and transport of photo-generated carriers. Here, a multiple aromatic ring spacer, 3-benzothiophene methylammonium (BTMA), is developed for a new 2D RP perovskite. The BTMA spacer is demonstrated, with a significant dipole moment, can impair the influence of the quantum confinement effect, and the presence of S atoms or thiophene is favorable for enhancing the interaction between organic spacers and inorganic sheets, improving the stability of perovskites. The perovskite photodetector with BTMA as spacers displays higher device performance than the control sample with 1-naphthalene methylammonium (NMA) as spacers. Importantly, the outstanding stability of BTMA-based perovskite films and devices is also confirmed under moisture, heat, and illumination conditions. Combining the asymmetric coplanar nanogap electrode architecture, the photodetectors' enhanced responsivity, detectivity, and external quantum efficiency of 314 A W−1, 3.4 × 1013 Jones, and 865%, respectively, are demonstrated. Importantly, the nanogap photodetectors display promising self-power characteristics, which makes them attractive for numerous energy-efficient applications. The work highlights a new route toward developing high-performance 2D RP perovskite-based photodetectors with excellent long-term stability.

DOI： 10.1002/adfm.202403746

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Scopus

Language：English   Publisher：Small  

As demand for higher integration density and smaller devices grows, silicon-based complementary metal-oxide-semiconductor (CMOS) devices will soon reach their ultimate limits. 2D transition metal dichalcogenides (TMDs) semiconductors, known for excellent electrical performance and stable atomic structure, are seen as promising materials for future integrated circuits. However, controlled and reliable doping of 2D TMDs, a key step for creating homogeneous CMOS logic components, remains a challenge. In this study, a continuous electrical polarity modulation of monolayer WS2 from intrinsic n-type to ambipolar, then to p-type, and ultimately to a quasi-metallic state is achieved simply by introducing controllable amounts of vanadium (V) atoms into the WS2 lattice as p-type dopants during chemical vapor deposition (CVD). The achievement of purely p-type field-effect transistors (FETs) is particularly noteworthy based on the 4.7 at% V-doped monolayer WS2, demonstrating a remarkable on/off current ratio of 105. Expanding on this triumph, the first initial prototype of ultrathin homogeneous CMOS inverters based on monolayer WS2 is being constructed. These outcomes validate the feasibility of constructing homogeneous CMOS devices through the atomic doping process of 2D materials, marking a significant milestone for the future development of integrated circuits.

DOI： 10.1002/smll.202402217

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PubMed

Publisher：Matter  

van der Waals (vdWs) dielectrics are widely used in nanoelectronics to preserve the intrinsic properties of two-dimensional (2D) semiconductors. However, achieving aligned growth of 2D semiconductors and their direct utilization on original vdWs epitaxial dielectrics to avoid disorders poses significant challenges. Here, a hydromechanical strategy for aligned epitaxy of 2D materials on naturally occurring vdWs mica dielectrics is developed. By combining density functional theory with Lagrange's group theorem, a quantitative criterion for 2D material epitaxy on 6-fold symmetric vdWs dielectrics is established. Moreover, the as-grown ultrathin Bi2O2Se-channeled field-effect transistor, with a hybrid dielectric layer, achieves a superior current on/off ratio (1.4 × 107) and high carrier mobility (22.4 cm2 V−1 S−1) by directly integrating as-grown 2D materials/vdWs dielectrics. This work provides a powerful methodological platform for aligned 2D material synthesis, alignment direction prediction, and intrinsic property investigation, laying the foundation for advanced electronics on as-grown 2D materials/vdWs dielectrics.

DOI： 10.1016/j.matt.2024.04.013

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Scopus

Publisher：Materials Today Electronics  

Perovskites have emerged as a promising new generation of photovoltaic conversion materials, gradually surpassing traditional silicon-based materials in solar cell research. This development is primarily due to their superior power-conversion efficiency (PCE), simple fabrication process, and cost-effective production. However, the low stability of perovskite ionic crystals poses a significant challenge to their stability, hindering the progress of perovskite materials and devices. Although two-dimensional (2D) perovskites offer improved stability, adding organic amine ions results in a quantum confinement effect that reduces the optoelectronic performance of devices. To counter this issue, the strategic design of suitable spacer cations offers a potential solution. Aromatic amine ions possess greater polarity and structural adjustability compared to aliphatic amine ions, making them advantageous in mitigating the quantum confinement effect. This review focuses on phenylethylammonium (PEA) as a representative aromatic spacer cation. It categorizes the evolution of these cations into four trajectories: alkyl chain modification, substitution of hydrogen atoms on the aromatic ring with specific substituents, replacement of benzene rings with aromatic heterocycles, and utilization of multiple aromatic rings instead of a monoaromatic ring. The structure, properties, and corresponding device performance of aromatic spacer cations utilized in reported 2D perovskites are discussed, followed by the presentation of a series of factors for selecting and designing aromatic amine ions for future development.

DOI： 10.1016/j.mtelec.2024.100100

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Scopus

Publisher：Advanced Optical Materials  

Van der Waals (vdW) heterostructures have gained significant attention in photodetectors due to their seamless integration with materials possessing diverse functionalities. In this study, the fabrication of a Te nanomesh/black-Si vdW heterostructure is presented, and investigated its photoresponse properties. The heterostructure exhibits a pronounced rectification behavior, characterized by a rectification ratio of 2.2 × 104. Notably, the heterostructure device demonstrates commendable photoresponse properties, including a high responsivity of 350 mA W−1, an extensive linear dynamic range of 45.5 dB, a high specific detectivity of 9.6 × 1011 Jones, and a wide spectral response ranging from 400 to 1550 nm. Furthermore, the heterostructure exhibits rapid response, with a rise time and a decay time of 70 and 140 µs, respectively. These exceptional photoresponse properties can be attributed to the robust internal built-in electrical field at the hetero-interface and the augmented light absorption in black-Si. The outstanding photoresponse properties of the heterostructure make it a promising candidate for multiwavelength single-pixel imaging, enabling the collection of mask patterns under varying wavelengths of light radiation. This work provides a novel approach for fabricating mixed-dimensional vdW heterostructures, offering promising prospects for advancements in optoelectronics.

DOI： 10.1002/adom.202400056

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Scopus

Language：English   Publisher：Nature Communications  

Inorganic semiconductors typically have limited p-type behavior due to the scarcity of holes and the localized valence band maximum, hindering the progress of complementary devices and circuits. In this work, we propose an inorganic blending strategy to activate the hole-transporting character in an inorganic semiconductor compound, namely tellurium-selenium-oxygen (TeSeO). By rationally combining intrinsic p-type semimetal, semiconductor, and wide-bandgap semiconductor into a single compound, the TeSeO system displays tunable bandgaps ranging from 0.7 to 2.2 eV. Wafer-scale ultrathin TeSeO films, which can be deposited at room temperature, display high hole field-effect mobility of 48.5 cm2/(Vs) and robust hole transport properties, facilitated by Te-Te (Se) portions and O-Te-O portions, respectively. The nanosphere lithography process is employed to create nanopatterned honeycomb TeSeO broadband photodetectors, demonstrating a high responsibility of 603 A/W, an ultrafast response of 5 μs, and superior mechanical flexibility. The p-type TeSeO system is highly adaptable, scalable, and reliable, which can address emerging technological needs that current semiconductor solutions may not fulfill.

DOI： 10.1038/s41467-024-48628-z

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Scopus

PubMed

Publisher：Advanced Functional Materials  

Zinc (Zn) has arisen as a significant suppressor of vacancy formation in halide perovskites, establishing its pivotal role in defect engineering for these materials. Herein, the Zn-catalyzed vapor-liquid-solid (VLS) route is reported to render black-phase CsPbI<inf>3</inf> nanowires (NWs) operationally stable at room temperature. Based on first-principle calculations, the doped Zn²⁺ can not only lead to the partial crystal lattice distortion but also reduce the formation energy (absolute value) from the black phase to the yellow phase, improving the stability of the desired black-phase CsPbI<inf>3</inf> NWs. A series of contrast tests further confirm the stabilization effect of the Zn-doped strategy. Besides, the polarization-sensitive characteristics of black-phase CsPbI<inf>3</inf> NWs are revealed. This work highlights the importance of phase stabilization engineering for CsPbI<inf>3</inf> NWs and their potential applications in anisotropic optoelectronics.

DOI： 10.1002/adfm.202314309

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Scopus

Language：English   Publisher：Nano Letters  

Time-resolved or time-correlation measurements using cathodoluminescence (CL) reveal the electronic and optical properties of semiconductors, such as their carrier lifetimes, at the nanoscale. However, halide perovskites, which are promising optoelectronic materials, exhibit significantly different decay dynamics in their CL and photoluminescence (PL). We conducted time-correlation CL measurements of CsPbBr<inf>3</inf> using Hanbury Brown-Twiss interferometry and compared them with time-resolved PL. The measured CL decay time was on the order of subnanoseconds and was faster than PL decay at an excited carrier density of 2.1 × 10¹⁸ cm^-3. Our experiment and analytical model revealed the CL dynamics induced by individual electron incidences, which are characterized by highly localized carrier generation followed by a rapid decrease in carrier density due to diffusion. This carrier diffusion can play a dominant role in the CL decay time for undoped semiconductors, in general, when the diffusion dynamics are faster than the carrier recombination.

DOI： 10.1021/acs.nanolett.4c00483

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Scopus

PubMed

Publisher：Applied Physics Reviews  

The Von Neumann architecture has been the foundation of modern computing systems. Still, its limitations in processing large amounts of data and parallel processing have become more apparent as computing requirements increase. Neuromorphic computing, inspired by the architecture of the human brain, has emerged as a promising solution for developing next-generation computing and memory devices with unprecedented computational power and significantly lower energy consumption. In particular, the development of optoelectronic artificial synaptic devices has made significant progress toward emulating the functionality of biological synapses in the brain. Among them, the potential to mimic the function of the biological eye also paves the way for advancements in robot vision and artificial intelligence. This review focuses on the emerging field of optoelectronic artificial synapses and memristors based on low-dimensional nanomaterials. The unique photoelectric properties of these materials make them ideal for use in neuromorphic and optoelectronic storage devices, with advantages including high carrier mobility, size-tunable optical properties, and low resistor-capacitor circuit delay. The working mechanisms, device structure designs, and applications of these devices are also summarized to achieve truly sense-storage-computer integrated optoelectronic artificial synapses.

DOI： 10.1063/5.0173547

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Scopus

Publisher：Device  

The incapability of effective multifunctional logic operations for most reported heterostructure electronic devices has impeded further simplification of the prevailing complex integrated circuit design. Here, an anti-ambipolar transistor is successfully demonstrated based on a mixed-dimensional GaAsSb nanowire/MoS<inf>2</inf> nanoflake heterojunction. Due to the strong interfacial coupling and band-structure alignment properties, the prominent anti-ambipolar transfer characteristics with the flipping of transconductance are readily achieved, showing a high peak-to-valley ratio of over 10³ on either side of the peak current. The anti-ambipolar transistor is then leveraged to perform the multivalued inverter with low supply voltage. Furthermore, the frequency doubling circuits are explored by exploiting the flipping of transconductance of the heterotransistor. The output voltage of the frequency multiplier oscillates at a 2-fold frequency in response to the input analog circuit signal. The mixed-dimensional anti-ambipolar transistors developed in this study are a step toward next-generation multifunctional integrated circuits and telecommunication technologies.

DOI： 10.1016/j.device.2023.100184

Web of Science

Scopus

Language：English   Publisher：Small  

Crystalline/amorphous phase engineering is demonstrated as a powerful strategy for electrochemical performance optimization. However, it is still a considerable challenge to prepare transition metal-based crystalline/amorphous heterostructures because of the low redox potential of transition metal ions. Herein, a facile H<inf>2</inf>-assisted method is developed to prepare ternary Ni<inf>2</inf>P/MoNiP<inf>2</inf>/MoP crystalline/amorphous heterostructure nanowires on the conductive substrate. The characterization results show that the content of the MoNiP<inf>2</inf> phase and the crystallinity of the MoP phase can be tuned by simply controlling the H<inf>2</inf> concentration. The obtained electrocatalyst exhibits a superior alkaline hydrogen evolution reaction performance, delivering overpotentials of 20 and 76 mV to reach current densities of 10 and 100 mA cm⁻² with a Tafel slope of 30.6 mV dec⁻¹, respectively. The catalysts also reveal excellent stability under a constant 100 h operation, higher than most previously reported electrocatalysts. These striking performances are ascribed to the optimized hydrogen binding energy and favorable hydrogen adsorption/desorption kinetics. This work not only exhibits the potential application of ternary Ni<inf>2</inf>P/MoNiP<inf>2</inf>/MoP crystalline/amorphous heterostructure nanowires catalysts for practical electrochemical water splitting, but also paves the way to prepare non-noble transition metal-based electrocatalysts with optimized crystalline/amorphous heterostructures.

DOI： 10.1002/smll.202304546

Web of Science

Scopus

PubMed

Publisher：Journal of Materiomics  

Organic-inorganic halide perovskite, as a low-cost, solution-processable material with remarkable optoelectronic properties, is ideal candidate to fabricate high-performance photodetectors and is expected to significantly reduce device costs. Compared to the common Dion-Jacobson and Ruddlesden-Popper two-dimensional (2D) layered hybrid perovskite compounds, the perovskites with alternating cations in the interlayer (ACI) phase show higher crystal symmetry and narrower optical bandgaps, which exhibit great potential for excellent photodetection performance. Herein, we report a high-performance photodetector based on the 2D bilayered hybrid lead halide perovskite single crystal with the ACI phase (GAMA2Pb2I7; GA = C(NH2)3 and MA = CH3NH3). The single-crystal photodetector exhibits high photoresponsivity of 1.56, 2.54, and 2.60 A/W for incident light wavelengths of 405, 532, and 635 nm under 9.82 nW, respectively, together with the correspondingly high detectivity values of 1.86 × 1012, 3.04 × 1012, and 3.11 × 1012 Jones under the same operating conditions. Meanwhile, a high-resolution imaging sensor is built based on the GAMA2Pb2I7 single-crystal photodetector, confirming the high stability and photosensitivity of the imaging system. These results show that the 2D hybrid lead halide perovskites with alternating interlayer cations are promising for high-performance visible light photodetectors and imaging systems.

DOI： 10.1016/j.jmat.2023.05.003

Web of Science

Scopus

Language：English   Publisher：Wiley  

Halide perovskites have attracted significant recent attention due to their remarkable photoelectric properties; however, the poor structural and moisture stability limit their use for practical utilization. Interestingly, binary halides, such as BiI3 and PbI2, are the typical constituents of halide perovskites, where they do not only have the similar outstanding properties of perovskites but also the superior stability. Herein, the synthesis of layered BiI3 and PbI2 microcrystals by simple drop-casting is investigated and their enhanced photoelectric performance compared to the thin-film counterparts obtained by conventional spin-coating is demonstrated. For the formation of high-quality layered microcrystals, the keys are adopting glycol as a green solvent and appropriate temperature during processing. Once configured into photodetectors, the BiI3 and PbI2 microcrystals exhibit a higher photocurrent, on/off current ratio, responsivity, and other performance parameters than their thin-film devices. These improved performances of microcrystals can be attributed to their superior crystallinity, thanks to the excellent solvent properties of glycol and the optimal growth temperature chosen. This work proposes a more simple and effective solution processing technique to fabricate layered binary halides with higher quality than the conventional spin-coating method, enabling the further development of halides-based optoelectronic devices.

CiNii Research

Publisher：Nano Research  

Due to the exciting photoelectric properties, better stability, and environmental-friendly nature, all-inorganic halide perovskites (AIHPs), especially the lead-free perovskites, have attracted worldwide attention. However, the film quality of AIHPs fabricated by typical spin-coating and subsequent high-temperature annealing is still not satisfactory, restricting their further development. Herein, we demonstrate a simple low-temperature solution-processed drop-casting method to achieve highly-crystalline cubic CsPbBr3 and lead-free layer-structured Cs3Sb2I9 microcrystals (MCs). This drop-casting technique not only consumes the less amount of precursor solution but also eliminates the high-temperature annealing as compared with those of spin coating. When these MCs are configured into photodetectors, they exhibit superior device performance, which is in distinct contrast to the one of spin-coated counterparts. Specifically, the responsivity of CsPbBr3 MCs is found to be as large as 8,990 mA/W, being 13 times larger than the spin-coated films and even better than many state-of-the-art solution-processed AIHPs devices. This device performance enhancement is attributed to the better film quality and phase purity obtained by the drop-casting method. All these results can evidently fill the “technology gap” for further enhancing the material quality of solution-processed AIHPs and breaking down the barriers that hinder the development of AIHPs based optoelectronic devices. [Figure not available: see fulltext.]

DOI： 10.1007/s12274-021-3907-9

Web of Science

Scopus

Publisher：APL Materials  

CsPb2Br5/CsPbBr3 composite systems have received considerable attention among numerous lead halide perovskite materials due to their significantly enhanced photoluminescence intensity and stability against moisture. However, the luminescence mechanism of CsPb2Br5 based materials remains controversial, which significantly hinders the further material design and utilization for optoelectronic devices. In this work, to deconvolute their luminescent mechanisms, high-quality CsPb2Br5 crystals without any undesired by-products and impurities have been first prepared by a microwave-assisted synthesis method. The luminescence-inactive characteristics of the material are then confirmed by the steady-state absorption, photoluminescence, transient absorption spectra, and time-resolved terahertz spectroscopy. The prepared CsPb2Br5 crystals exhibit excellent crystallinity and enhanced thermal stability, particularly that they can maintain their crystalline structures in polar organic solvents. By simply manipulating the ratios of different precursor materials, it is witnessed that the green emission comes from the CsPbBr3 adhered, nucleated, and grown on the CsPb2Br5 crystals. Ultrafast transient absorption measurements in visible and terahertz spectral regions reveal that with the help of phonon scattering-assisted hopping at interfacial states, intersystem crossing dominates the electron transfer process in the composite crystals. As a result, the CsPb2Br5 and CsPbBr3 interact extensively with each other. Meanwhile, the Auger recombination rate and the defect-related non-radiative process are suppressed in the composite crystals, thereby enhancing the fluorescence of composite crystals. This work has not only deconvoluted the controversial and unclear luminescent mechanisms of CsPb2Br5 materials but also established a pathway to design and enhance the fluorescence of materials for technological applications.

DOI： 10.1063/5.0083022

Web of Science

Scopus