The high-quality semipolar (112̅2) AlGaN epitaxial films have been obtained on m-plane sapphire by metal-organic chemical vapor deposition. X-ray rocking curve measurements show the full-width at half-maximums of (112̅2)-oriented are 0.357° and 0.531° along [112̅3̅]AlGaN [11̅00]AlGaN, respectively. fabricated metal-semiconductor-metal solar-blind ultraviolet (UV) photodetector (PD) exhibits a high responsivity 1842 A/W. fast response reliability UV PD ensured via switching with rise decay...

Counting the number of transplanted crops is a crucial link in agricultural production, serving as key method to promptly obtain information on crop growth conditions and ensure yield quality. The existing counting methods primarily rely manual or estimation, which are inefficient, costly, difficult evaluate statistically. Additionally, some deep-learning-based algorithms can only large-scale remote sensing images obtained by Unmanned Aerial Vehicles (UAVs) into smaller sub-images for...

Homoepitaxially grown InGaN/GaN light emitting diodes (LEDs) with SiO2 nanodisks embedded in n-GaN and p-GaN as photonic crystal (PhC) structures by nanospherical-lens photolithography are presented investigated. The introduction of doesn't produce the new dislocations also result electrical deterioration PhC LEDs. output power homoepitaxial LEDs double at 350 mA current is increased 29.9% 47.2%, respectively, compared to that without PhC. corresponding radiation patterns on GaN substrate...

In this work, we fabricated and characterized 4 × parallel flip-chip AlGaN-based micro-LED arrays with varied mesa diameters of 120 µm, 100 80 60 µm. The reported have a maximum bandwidth 380 MHz peak wavelength ∼275 nm. It is found that the electrical optical characteristics show strong size dependence for ultraviolet communication (UVC). differential resistance increases from 28.8 Ω to 112 Ω, external quantum efficiency (EQE) increased by ∼30%, doubles as diameter individual decreases µm...

The heteroepitaxy of high-quality aluminum nitride (AlN) with low stress is essential for the development energy-efficient deep ultraviolet light-emitting diodes (DUV-LEDs). In this work, we realize that quasi-van der Waals epitaxy growth a stress-released AlN film dislocation density on hexagonal boron (h-BN)/sapphire suffered from high-temperature annealing (HTA) treatment and demonstrate its application in DUV-LED. It revealed HTA effectively improves crystalline quality surface...

Thick nonpolar (1010) GaN layers were grown on m-plane sapphire substrates by hydride vapor phase epitaxy (HVPE) using magnetron sputtered ZnO buffers, while semipolar (1013) obtained the conventional two-step growth method same substrate. The in-plane anisotropic structural characteristics and stress distribution of epilayers revealed high resolution X-ray diffraction polarized Raman scattering measurements. Atomic force microscopy (AFM) images that striated surface morphologies correlated...

We report on the high-performance nanoporous (NP) GaN-based metal-insulator-semiconductor (MIS) ultraviolet (UV) photodetectors (PDs) with a thermal oxidized β-Ga2O3insulating layer. The devices show high responsivity of 4.5×105 A/W and maximum external quantum efficiency 1.55×108% at 360 nm under 10 V applied bias, which are attributed to trap-assisted tunneling induced internal gain mechanism. Correspondingly, specific detectivity 8.27×1015 Jones excellent optical switching repeatability...

Semipolar (11–22) AlN films grown on m-plane sapphire are investigated by flow-rate modulation epitaxy (FME). The full width of half maximums (FWHMs) thin film for X-ray rocking curves (XRCs) reduced from 1398 arcsec traditional growth to 865 III-FME. defect density is attributed prolonged Al mobility, which results in the transition mode quasi three-dimensional two-dimensional step flow. On-axis FWHM[11–23] and off-axis FWHM[0002] XRCs 6 μm-thick III-FME 346 641 arcsec, respectively....

In this work, we present a stress-free AlN film with improved crystal quality assisted by h-BN and demonstrate the mechanical exfoliation of wafer-scale single-crystal freestanding membrane reveal controllable mechanism AlN. Uniform continuous is directly grown on c-plane sapphire using flow modulation epitaxy mode metal-organic chemical vapor deposition. The nucleation evolution processes quasi-van der Waals (QvdWE) are revealed. It found that O2-plasma-treated can effectively promote...

Abstract Robotic grippers have been used in industry as end-effectors but are usually limited to operations pre-defined workspace. However, few devices can capture irregularly shaped dynamic targets space, underwater and other unstructured environments. In this paper, a novel continuum arm group mechanism inspired by the morphology motions of sea anemones is proposed. It able dissipate absorb kinetic energy fast moving target omni-direction utilize multiple arms wrap lock without accurate...

Graphene on gallium nitride (GaN) will be quite useful when the graphene is used as transparent electrodes to improve performance of devices. In this work, we report direct synthesis GaN without an extra catalyst by chemical vapor deposition. Raman spectra indicate that films are uniform and about 5–6 layers in thickness. Meanwhile, effects growth temperatures systematically studied, which 950 °C found optimum temperature. The sheet resistance grown 41.1 Ω/square, close lowest transferred...

Abstract We report a novel method to fabricate high quality 2-inch freestanding GaN substrate grown on cross-stacked carbon nanotubes (CSCNTs) coated sapphire by hydride vapor phase epitaxy (HVPE). As nanoscale masks, these CSCNTs can help weaken the interface connection and release compressive stress forming voids during fast coalescence also block propagation of threading dislocations (TDs). During cool-down process, thermal stress-induced cracks are initiated at with air propagated all...

High-temperature annealing (HTA) has been recognized as an available method to annihilate the domain boundaries and improve crystalline quality of AlN films. Here, semipolar (112̅2) films through HTA process are utilized prepare vacuum ultraviolet photodetectors (VUV PDs). The resulting show full widths at half-maximum high-resolution X-ray rocking curves that 527 622 arcsec along [112̅3̅]AlN [11̅00]AlN, respectively, which illustrates much improved compared previous reports. not only...

Two-dimensional material MoS2 has excellent optical and electrical characteristics a controllable energy band structure, leading to high potential value for designing photodetectors. In this work, kind of van der Waals heterostructure composed AlN photodetector was fabricated. The properties can be improved by the polarization effect AlN. On basis, with 3 nm thick Al2O3 layer deposited on layer, strain effects were also investigated improve performance detector. result showed that under an...

The detection of explosive agents is becoming more important and receiving much greater emphasis for homeland defense. Raman spectroscopy a well established tool vibration spectroscopic analysis can be applied to the field explosives identification detection. major bands industrial TNT (Trinitrotoluene, CH₃C₆H₂(NO₂)₃) are analyzed seven prominent peaks, that 1616.9cm^-1 (C=C aromatic stretching vibration), 1533.9cm^-1...

Light-Emitting Diodes In article number 2306132, Tongbo Wei and co-workers demonstrate a pioneering technology for growing 3D semiconductor films on 2D materials, namely van der Waals epitaxy, which both relaxes the lattice thermal matching requirements between epilayer substrate, enables exfoliation of epilayers flexible optoelectronic devices, such as displays.

Abstract As a promising technology for next-generation displays due to their high brightness and low power consumption, InGaN-based micro light-emitting diodes (Micro-LEDs) have attracted great attention in recent years. In this work, we detailedly investigate the carrier recombination transportation process dual-wavelength InGaN/GaN multiple quantum wells (MQWs) Micro-LED arrays under piezo-phototronic effects using electroluminescence (EL) time-resolution photoluminescence measurements....