Band Alignment Semimetal Heterojunction-Based Ultrabroadband Photodetector for Noncontact Gesture Interaction with Low Latency.

Non-contact gesture recognition and interaction (NGRI) revolutionizes the natural user interface, fundamentally transforming human interactions with daily-use technology. Conventional NGRI systems frequently encounter obstacles such as pronounced latency and environmental disturbances, including humidity or lighting conditions, resulting in compromised system fluidity and robustness. This study highlights the utilization of silicon-based semimetal heterojunction photodetectors for precise gesture recognition and seamless human-machine interaction.

Differential pressure sensors based on transfer-free piezoresistive layered PdSethin films.

Piezoresistive layered two-dimensional (2D) crystals offer intriguing promise as pressure sensors for microelectromechanical systems (MEMS) due to their remarkable strain-induced conductivity modulation. However, integration of the conventional chemical vapor deposition grown 2D thin films onto a micromachined silicon platform requires a complex transfer process, which degrades their strain-sensing performance. In this study, we present a differential pressure sensor built on a transfer-free piezoresistive PdSepolycrystalline film deposited on a SiNmembrane by plasma-enhanced selenization of a metal film at a temperature as low as 200 °C.

Pulse irradiation synthesis of metal chalcogenides on flexible substrates for enhanced photothermoelectric performance.

High synthesis temperatures and specific growth substrates are typically required to obtain crystalline or oriented inorganic functional thin films, posing a significant challenge for their utilization in large-scale, low-cost (opto-)electronic applications on conventional flexible substrates. Here, we explore a pulse irradiation synthesis (PIS) to prepare thermoelectric metal chalcogenide (e.g.

Interfacial Charge Transfer for Enhancing Nonlinear Saturable Absorption in WS/graphene Heterostructure.

Interlayer charge-transfer (CT) in 2D atomically thin vertical stacks heterostructures offers an unparalleled new approach to regulation of device performance in optoelectronic and photonics applications. Despite the fact that the saturable absorption (SA) in 2D heterostructures involves highly efficient optical modulation in the space and time domain, the lack of explicit SA regulation mechanism at the nanoscale prevents this feature from realizing nanophotonic modulation. Here, the enhancement of SA response via CT in WS/graphene vertical heterostructure is proposed and the related mechanism is demonstrated through simulations and experiments.

Genetic algorithm-based optical proximity correction for DMD maskless lithography.

We present an optical proximity correction (OPC) method based on a genetic algorithm for reducing the optical proximity effect-induced pattern distortion in digital micromirror device (DMD) maskless lithography. Via this algorithm-assisted grayscale modulation of the initial mask at the pixel level, the exposure pattern can be enhanced significantly. Actual exposure experiments revealed that the rate of matching between the final exposure pattern and the mask pattern can be increased by up to 20%.

Thickness-dependent carrier transport of PdSefilms grown by plasma-assisted metal selenization.

Atomically thin narrow-bandgap layered PdSehas attracted much attention due to its rich and unique electrical properties. For silicon-compatible device integration, direct wafer-scale preparation of high-quality PdSethin film on a silicon substrate is highly desired. Here, we present the low-temperature synthesis of large-area polycrystalline PdSefilms grown on SiO/Si substrates by plasma-assisted metal selenization and investigate their charge carrier transport behaviors.

Van der Waals nanomesh electronics on arbitrary surfaces.

Chemical bonds, including covalent and ionic bonds, endow semiconductors with stable electronic configurations but also impose constraints on their synthesis and lattice-mismatched heteroepitaxy. Here, the unique multi-scale van der Waals (vdWs) interactions are explored in one-dimensional tellurium (Te) systems to overcome these restrictions, enabled by the vdWs bonds between Te atomic chains and the spontaneous misfit relaxation at quasi-vdWs interfaces. Wafer-scale Te vdWs nanomeshes composed of self-welding Te nanowires are laterally vapor grown on arbitrary surfaces at a low temperature of 100 °C, bringing greater integration freedoms for enhanced device functionality and broad applicability.

Gate-bias instability of few-layer WSe field effect transistors.

Semiconducting two-dimensional (2D) layered materials have shown great potential in next-generation electronics due to their novel electronic properties. However, the performance of field effect transistors (FETs) based on 2D materials is always environment-dependent and unstable under gate bias stress. Here, we report the environment-dependent performance and gate-induced instability of few-layer p-type WSe-based FETs.

Gate Bias Stress Instability and Hysteresis Characteristics of InAs Nanowire Field-Effect Transistors.

Because of the excellent electrical properties, III-V semiconductor nanowires are promising building blocks for next-generation electronics; however, their rich surface states inevitably contribute large amounts of charge traps, leading to gate bias stress instability and hysteresis characteristics in nanowire field-effect transistors (FETs). Here, we investigated thoroughly the gate bias stress and hysteresis effects in InAs nanowire FETs. It is observed that the output current decreases together with the threshold voltage shifting to the positive direction when a positive gate bias stress is applied, and vice versa for the negative gate bias stress.

Artificial visual systems enabled by quasi-two-dimensional electron gases in oxide superlattice nanowires.

Rapid development of artificial intelligence techniques ignites the emerging demand on accurate perception and understanding of optical signals from external environments via brain-like visual systems. Here, enabled by quasi-two-dimensional electron gases (quasi-2DEGs) in InGaO(ZnO) superlattice nanowires (NWs), an artificial visual system was built to mimic the human ones. This system is based on an unreported device concept combining coexistence of oxygen adsorption-desorption kinetics on NW surface and strong carrier quantum-confinement effects in superlattice core, to resemble the biological Ca ion flux and neurotransmitter release dynamics.

2D materials beyond graphene toward Si integrated infrared optoelectronic devices.

Since the discovery of graphene in 2004, it has become a worldwide hot topic due to its fascinating properties. However, the zero band gap and weak light absorption of graphene strictly restrict its applications in optoelectronic devices. In this regard, semiconducting two-dimensional (2D) materials are thought to be promising candidates for next-generation optoelectronic devices.

Graphene/WS heterostructure saturable absorbers for ultrashort pulse generation in L-band passively mode-locked fiber lasers.

Graphene/WS (G/WS) van der Waals (vdW) heterostructures are utilized as saturable absorbers (SAs) in compact mode-locked fiber lasers operating in the telecommunication L-band for the first time. The interlayer coupling is confirmed by Raman and photoluminescence spectra. In comparison with pure WS, the heterostructure exhibits excellent nonlinear optical properties in terms of larger modulation depth and lower saturation intensity due to the strong interlayer coupling.

High-Performance Transparent Ultraviolet Photodetectors Based on InGaZnO Superlattice Nanowire Arrays.

Due to the efficient photocarrier separation and collection coming from their distinctive band structures, superlattice nanowires (NWs) have great potential as active materials for high-performance optoelectronic devices. In this work, InGaZnO NWs with superlattice structure and controllable stoichiometry are obtained by ambient-pressure chemical vapor deposition. Along the NW axial direction, perfect alternately stacking of InGaO(ZnO) blocks and InO layers is observed to form a periodic layered structure.

Utilizing a NaOH Promoter to Achieve Large Single-Domain Monolayer WS Films via Modified Chemical Vapor Deposition.

Because of their fascinating properties, two-dimensional (2D) nanomaterials have attracted a lot of attention for developing next-generation electronics and optoelectronics. However, there is still a lack of cost-effective, highly reproducible, and controllable synthesis methods for developing high-quality semiconducting 2D monolayers with a sufficiently large single-domain size. Here, utilizing a NaOH promoter and W foils as the W source, we have successfully achieved the fabrication of ultralarge single-domain monolayer WS films via a modified chemical vapor deposition method.

Engineering Surface Structure of Spinel Oxides via High-Valent Vanadium Doping for Remarkably Enhanced Electrocatalytic Oxygen Evolution Reaction.

Spinel oxides (ABO) with unique crystal structures have been widely explored as promising alternative catalysts for efficient oxygen evolution reactions; however, developing novel methods to fabricate robust, cost-effective, and high-performance spinel oxide based electrocatalysts is still a great challenge. Here, utilizing a complementary experimental and theoretical approach, pentavalent vanadium doping in the spinel oxides (i.e.

Ultra-fast photodetectors based on high-mobility indium gallium antimonide nanowires.

Because of tunable bandgap and high carrier mobility, ternary III-V nanowires (NWs) have demonstrated enormous potential for advanced applications. However, the synthesis of large-scale and highly-crystalline InGaSb NWs is still a challenge. Here, we achieve high-density and crystalline stoichiometric InGaSb (0.

Nonpolar-Oriented Wurtzite InP Nanowires with Electron Mobility Approaching the Theoretical Limit.

As an important semiconductor nanomaterial, InP nanowires (NWs) grown with a typical vapor-liquid-solid mechanism are still restricted from their low electron mobility for practical applications. Here, nonpolar-oriented defect-free wurtzite InP NWs with electron mobility of as high as 2000 cm V s can be successfully synthesized via Pd-catalyzed vapor-solid-solid growth. Specifically, PdIn catalyst particles are involved and found to expose their PdIn{210} planes at the InP nucleation frontier due to their minimal lattice mismatch with nonpolar InP{2̅110} and {1̅100} planes.

Novel Series of Quasi-2D Ruddlesden-Popper Perovskites Based on Short-Chained Spacer Cation for Enhanced Photodetection.

Quasi two-dimensional (2D) layered organic-inorganic perovskite materials (e.g., (BA)(MA) Pb I; BA = butylamine; MA = methylamine) have recently attracted wide attention because of their superior moisture stability as compared with three-dimensional counterparts.

Facile large-area autofocusing Raman mapping system for 2D material characterization.

Two-dimensional (2D) materials have attracted tremendous research interests due to their intriguing properties and promising applications. As one of the most typical 2D material characterization methods, however, the conventional Raman mapping only works within few-hundreds micrometers range at a time due to the focus depth constraint and the non-ideal level of the substrate. To implement wafer-scale Raman scanning, large-area autofocusing Raman mapping (LARM) is highly desirable.

High-Index Faceted Porous CoO Nanosheets with Oxygen Vacancies for Highly Efficient Water Oxidation.

Because of sluggish kinetics of the oxygen evolution reaction (OER), designing low-cost, highly active, and stable electrocatalysts for OER is important for the development of sustainable electrochemical water splitting. Here, {112} high-index facet exposed porous CoO nanosheets with oxygen vacancies on the surface have been successfully synthesized via a simple hydrothermal method followed by NaBH reduction. As compared with the pristine and other faceted porous CoO nanosheets (e.

Large-Scale Synthesis of Freestanding Layer-Structured PbI and MAPbI Nanosheets for High-Performance Photodetection.

Recently, due to the possibility of thinning down to the atomic thickness to achieve exotic properties, layered materials have attracted extensive research attention. In particular, PbI , a kind of layered material, and its perovskite derivatives, CH NH PbI (i.e.

Transparent, flexible, and stretchable WS based humidity sensors for electronic skin.

Skin-mountable chemical sensors using flexible chemically sensitive nanomaterials are of great interest for electronic skin (e-skin) application. To build these sensors, the emerging atomically thin two-dimensional (2D) layered semiconductors could be a good material candidate. Herein, we show that a large-area WS film synthesized by sulfurization of a tungsten film exhibits high humidity sensing performance both in natural flat and high mechanical flexible states (bending curvature down to 5 mm).

Zener Tunneling and Photoresponse of a WS2/Si van der Waals Heterojunction.

Van der Waals heterostructures built from two-dimensional materials on a conventional semiconductor offer novel electronic and optoelectronic properties for next-generation information devices. Here we report that by simply stacking a vapor-phase-synthesized multilayer n-type WS2 film onto a p-type Si substrate, a high-responsivity Zener photodiode can be achieved. We find that above a small reverse threshold voltage of 0.

Reactive Sputter Deposition of WO3/Ag/WO3 Film for Indium Tin Oxide (ITO)-Free Electrochromic Devices.

Functioning both as electrochromic (EC) and transparent-conductive (TC) coatings, WO3/Ag/WO3 (WAW) trilayer film shows promising potential application for ITO-free electrochromic devices. Reports on thermal-evaporated WAW films revealed that these bifunctional WAW films have distinct EC characteristics; however, their poor adhesive property leads to rapid degradation of coloring-bleaching cycling. Here, we show that WAW film with improved EC durability can be prepared by reactive sputtering using metal targets.