Catalyst-free, direct heteroepitaxial growth of vertical InAs nanowires on Si(111) substrates was accomplished over a large area by metal−organic chemical vapor deposition. Nanowires showed very uniform diameters and zinc blende crystal structure. The heterojunctions formed at the interface between n-type p-type Si substrate were exploited to fabricate array photodiode devices which an excellent rectification ratio low reverse leakage current. Temperature-dependent current transport across...

Epitaxial growth of vertical GaAs nanowires on Si (111) substrates is demonstrated by metal−organic chemical vapor deposition via a vapor−liquid−solid mechanism. Systematic experiments indicate that substrate pretreatment, pregrowth alloying temperature, and temperature are all crucial to epitaxial growth. Nanowire rate morphology can be well controlled the precursor molar fraction, V/III ratio. The as-grown have predominantly zinc-blende crystal structure along ⟨111⟩ direction....

We demonstrate a nanowire (NW) phototransistor with synaptic behavior based on inherent persistent photoconductivity. The device is comprised of single crystalline InAs NW, covered by native indium oxide layer acting as the photogating (PGL). In negative photoresponse range, mimics neuromorphic behaviors short-term plasticity, long-term plasticity (LTP), and paired-pulse facilitation. Moreover, transition from to LTP observed stimulus intensity increases, behaving in accord feature...

We report the observation of energy transfer from a gold (Au) nanodisk pair to silver (Ag) nanowire across 120 nm gap via surface plasmon resonance (SPR) excitation. The enhanced electromagnetic (EM) fields generated by Au SPR excitation induce oscillation conduction electrons in Ag segment, transferring it even though segment has only weak resonant interactions with incident EM radiation. induced produces strong at position leading Raman signal ∼15 times greater than when is alone (not...

A plasmonic refractive index sensor based on a circular resonator is proposed. With all three dimensions below 1 μm, the has compact and simple structure granting it ease-of-fabrication ease-of-use. It capable of sensing trace amounts liquid or gas samples. The properties are investigated using finite elements method. results demonstrate that relatively high sensitivity 1,010 nm/RIU, corresponding resolution 9.9 × 10(-5) RIU. quality factor 35, which beneficial for identifying each...

High-efficiency and stable graphene–Si heterojunction solar cells without chemical doping were achieved through introducing a thin passivation layer of carbon nanowalls an antireflection film PMMA to increase light absorption.

We report the systematic study of catalyst-free syntheses InAs nanowires on Si substrates with various growth parameters and surface treatments. Nanowire morphology crystal structure were studied using scanning electron microscopy transmission microscopy. High-resolution cross-sectional studies reveal heteroepitaxy InAs[111] Si(111) substrate clean sharp interface. Single nanowire field-effect transistor measurements under optimal conditions indicate a typical concentration 1018–1019 cm–3...

This study proposed to determine whether in vivo iodine concentration measurement by single-source dual energy (SSDE) CT can improve differentiation between benign and malignant thyroid nodules. In total, 53 patients presenting with nodules underwent SSDE scanning. Iodine concentrations were measured for each nodule normal tissue using the GSI-viewer image analysis software. A total of 26 confirmed surgery; 33 from 27 benign, 10 surgery others after follow-up. plain significantly lower than...

A new method for measuring the dielectric functions change with thickness of nanometal thin films was proposed. To confirm accuracy and reliability method, a nano-thin wedge-shaped gold (Au) film continuously varied thicknesses designed prepared on K9 glass by direct-current-sputtering (DC-sputtering). The in wavelength range 300–1100 nm Au were obtained fitting ellipsometric parameters Drude critical points model. Results show that while real part function (ϵ1) changes marginally increasing...

Evanescent-wave pumped room-temperature single-mode GaAs/AlGaAs core-shell nanowire lasers are proposed and demonstrated. The nanowires axially excited by evanescent wave outside a microfiber with diameter about 10 μm via ns-pulse laser. lasing emission low effective threshold less than 90 nJ is achieved at 868.62 nm along linewidth of ∼1.8 nm. Moreover, multiple lines in wavelength range from 852.56 to 882.48 observed. mechanism diverse wavelengths revealed. Furthermore, the laser has...

Object detection in point clouds is a critical component most autonomous driving systems. In this paper, order to improve the effectiveness of image feature extraction and accuracy clouds, pillar-based 3D cloud object algorithm with multiattention mechanism proposed, which includes three attention mechanisms SOCA, SOPA, SAPI. The results show that recognition optimized for cars, pedestrians, cyclists on KITTI dataset significantly improved benchmarks BEV 3D. Despite using only LiDAR, our...

The photovoltaic performance of axial and radial pin junction GaAs nanocone array solar cells is investigated. Compared with the cylinder nanowire arrays, arrays not only improve whole optical absorption but more importantly enhance effective (absorption in depletion region). enhanced attributed to downward shift extension region induced by shrinking top, which dramatically suppresses loss high-doped top enhances region. highest conversion efficiencies for are 20.1% 17.4%, obtained at a...

A horizontally aligned GaAs p-i-n nanowire array solar cell is proposed and studied via coupled three-dimensional optoelectronic simulations. Benefiting from light-concentrating light-trapping properties, the horizontal yields a remarkable efficiency of 10.8% with radius 90 nm period 5 radius, more than twice that its thin-film counterpart same thickness. To further enhance absorption, placed on low-refractive-index MgF2 substrate capsulated in SiO2, which enables multiple reflection...

Depth estimation is requisite to build 3D perceiving capability of artificial intelligence things (AIoT). Real-time inference with extremely low computing resource consumption critical on edge devices. However, most single-view depth networks focus the improvement accuracy running high-end GPUs, which go opposite real-time requirement To address this issue, article proposed a novel encoder-decoder network realize monocular The merges semantic information at global field via an efficient...

Abstract An asymmetric hybrid plasmonic metal-wire waveguide is proposed by combining the advantages of symmetric and modes. The idea structure eliminates adverse effect a substrate enhances optical performance waveguide. guiding properties are intensively investigated using finite elements method. results exhibit quite long propagation length 2.69 cm with subwavelength confinement. More importantly, an extremely large figure merit 139037 achieved. Furthermore, waveguides can be used as...

Point cloud segmentation is a key prerequisite for object classification recognition. We propose fast region growing algorithm by using the neighborhood search, filter sampling, Euclidean clustering and growth. Segmentation experiment on point data in indoor environment demonstrated that accuracy efficiency were improved proposed algorithm.

Obstacle visualization and detection are essential parts of autonomous driving. The capability accurately rapidly collecting 3D information the surrounding environment plays a key role in driving decisions vehicles. As an active device, LiDAR enables high-speed real-time depth acquisition by emitting laser pulses then receiving echoes. However, frame rate density point cloud generated conventional LiDARs limited fixing trajectory beam-steering unit, which cannot satisfy requirements various...

Background The detection rate of lung nodules has increased considerably with CT as the primary method examination, and repeated examinations at 3 months, 6 months or annually, based on nodule characteristics, have radiation exposure patients. So, it is urgent to explore a radiation‐free MRI examination that can effectively address challenges posed by low proton density magnetic field inhomogeneities. Purpose To evaluate potential zero echo time (ZTE) in screening reporting data system...

Abstract A low-threshold nanolaser with all three dimensions at the subwavelength scale is proposed and investigated. The constructed based on an asymmetric hybrid plasmonic F-P cavity Ag-coated end facets. Lasing characteristics are calculated using finite element method wavelength of 1550 nm. results show that owing to low modal loss, large confinement factor structure, in conjunction high reflectivity Ag reflectors, a minimum threshold gain 240 cm −1 predicted. Furthermore, Purcell as...

We optimized the performance of GaAs nanowire pin junction array solar cells by introducing AlGaAs/GaAs heterejunctions. AlGaAs is used for p type top segment axial junctions and outer shell radial junctions. The not only serves as passivation layers nanowires but also confines optical generation in active regions, reducing recombination loss heavily doped regions minority carrier at contact. results show that conversion efficiency can be greatly enhanced using instead GaAs. A maximum...

A 140GHz electron cyclotron resonance heating and current drive (EC H&CD) project for EAST Tokamak is launched in 2011 with a total power of 4MW pulse length 100 s. The main objectives the system are to provide central H&CD, assist start-up control MHD activities. comprises four gyrotrons each nominal output 1MW at 140GHz. RF power, transmitted through evacuated corrugated waveguides will be injected into plasma from low field side (radial port). front steering equatorial launcher directs...