Read by QxMD icon Read

Silicon nanowire

Yuxiang Qin, Diao Liu, Tianyi Zhang, Zhen Cui
Surface functionalization is very effective in enhancing sensing properties of a chemiresistive gas sensor. In this work, we develop a novel and cost-effective process to prepare Ag-modified silicon nanowire (SiNW) sensors and further suggest a resistance effect model to clarify the enhanced sensing mechanism of Ag-modified SiNWs. The SiNWs were formed via metal-assisted chemical etching (MACE), and the Ag nanoparticle (NP) modification was achieved in situ based on the MACE-produced Ag dendrites by involving a crucial anisotropic postetching of TMAH...
August 16, 2017: ACS Applied Materials & Interfaces
Zhishan Yuan, Chengyong Wang, Ke Chen, Zhonghua Ni, Yunfei Chen
In this paper, amorphous silicon nanowires (α-SiNWs) were synthesized on (100) Si substrate with silicon oxide film by Cu catalyst-driven solid-liquid-solid mechanism (SLS) during annealing process (1080 °C for 30 min under Ar/H2 atmosphere). Micro size Cu pattern fabrication decided whether α-SiNWs can grow or not. Meanwhile, those micro size Cu patterns also controlled the position and density of wires. During the annealing process, Cu pattern reacted with SiO2 to form Cu silicide. More important, a diffusion channel was opened for Si atoms to synthesis α-SiNWs...
August 10, 2017: Nanoscale Research Letters
Eero Koivusalo, Teemu Hakkarainen, Mircea D Guina, Vladimir G Dubrovskii
Herein, we present experimental data on the record length uniformity within the ensembles of semiconductor nanowires. The length distributions of Ga-catalyzed GaAs nanowires obtained by cost-effective lithography-free technique on silicon substrates systematically feature a pronounced sub-Poissonian character. For example, nanowires with the mean length of 2480 nm show a length distribution variance of only 367 nm2, which is more than twice smaller than the Poisson variance of 808 nm2 for this mean length (with = 0...
August 7, 2017: Nano Letters
Matteo Salvato, Reza Baghdadi, Carla Cirillo, Serghej L Prischepa, Alexey Dolgiy, Vitaly Bondarenko, Floriana Lombardi, Carmine Attanasio
Superconducting NbN nanonetworks with a very small number of interconnected nanowires, with diameter of the order of 4 nm, are fabricated combining a bottom-up (use of porous silicon nanotemplates) with a top-down technique (high-resolution electron beam lithography). The method is easy to control and allows to fabricate, on a robust support, devices with electrical properties close to a one-dimensional superconductor that can be fruitfully used for novel applications.
August 7, 2017: Nanotechnology
Brian Ford, Natasha Tabassum, Vasileios Nikas, Spyros Gallis
The following study focuses on the photoluminescence (PL) enhancement of chemically synthesized silicon oxycarbide (SiCxOy) thin films and nanowires through defect engineering via post-deposition passivation treatments. SiCxOy materials were deposited via thermal chemical vapor deposition (TCVD), and exhibit strong white light emission at room-temperature. Post-deposition passivation treatments were carried out using oxygen, nitrogen, and forming gas (FG, 5% H₂, 95% N₂) ambients, modifying the observed white light emission...
April 23, 2017: Materials
Zhen-Qiang Ye, Bing-Yang Cao
Thermal rectification can help develop modern thermal manipulation devices but has been rarely engineered. Here, we validated the nanoscale bimaterial interface-induced thermal rectification experimentally for the first time and investigated its underlying mechanism via molecular dynamics simulations. The thermal diode consists of polyamide (PA) and silicon (Si) nanowires in contact with each other. The thermal rectification ratio measured by a high-precision nanoscale experiment reached 4% with an uncertainty of <1%...
August 2, 2017: Nanoscale
Hyunseok Kim, Wook-Jae Lee, Alan C Farrell, Akshay Balgarkashi, Diana L Huffaker
Semiconductor nanowire lasers are considered promising ultracompact and energy-efficient light sources in the field of nanophotonics. Although the integration of nanowire lasers onto silicon photonic platforms is an innovative path toward chip-scale optical communications and photonic integrated circuits, operating nanowire lasers at telecom-wavelengths remains challenging. Here, we report on InGaAs nanowire array lasers on a silicon-on-insulator platform operating up to 1440 nm at room temperature. Bottom-up photonic crystal nanobeam cavities are formed by growing nanowires as ordered arrays using selective-area epitaxy, and single-mode lasing by optical pumping is demonstrated...
August 2, 2017: Nano Letters
Liye Zhang, Junshan Yin, Wei Yu, Mingzhu Wang, Huaqing Xie
In this paper, ultra-long copper nanowires (CuNWs) were successfully synthesized at a large scale by hydrothermal reduction of divalent copper ion using oleylamine and oleic acid as dual ligands. The characteristic of CuNWs is hard and linear, which is clearly different from graphene nanoplatelets (GNPs) and multi-wall carbon nanotubes (MWCNTs). The thermal properties and models of silicone composites with three nanomaterials have been mainly researched. The maximum of thermal conductivity enhancement is up to 215% with only 1...
December 2017: Nanoscale Research Letters
Zi Wang, Zhongyu Hou
A room-temperature routine for the fabrication of a three-dimensional silicon porous framework inspired by a polymer foaming process is introduced. The obtained micron-sized pores can be further modified by hydrothermal growth of nanowires to form a hierarchical porous composite framework.
July 24, 2017: Chemical Communications: Chem Comm
Juan Arturo Alanis, Dhruv Saxena, Sudha Mokkapati, Nian Jiang, Kun Peng, Xiaoyan Tang, Lan Fu, Hark Hoe Tan, Chennupati Jagadish, Patrick Parkinson
Single nanowire lasers based on bottom-up III-V materials have been shown to exhibit room-temperature near-infrared lasing, making them highly promising for use as nanoscale, silicon-integrable, and coherent light sources. While lasing behavior is reproducible, small variations in growth conditions across a substrate arising from the use of bottom-up growth techniques can introduce interwire disorder, either through geometric or material inhomogeneity. Nanolasers critically depend on both high material quality and tight dimensional tolerances, and as such, lasing threshold is both sensitive to and a sensitive probe of such inhomogeneity...
July 25, 2017: Nano Letters
Hao Cui, Shuoyu Li, Shaozhi Deng, Huanjun Chen, Chengxin Wang
We demonstrated a flexible transparent and free-standing Si nanowire paper (SiNWP) as a surface enhanced Raman scattering (SERS) platform for in situ chemical sensing on warping surfaces with high sensitivity. The SERS activity has originated from the three-dimension interconnected nanowire network structure and electromagnetic coupling between closely separated nanowires in the SiNWP. In addition, the SERS activity can be highly improved by functionalizing the SiNWP with plasmonic Au nanoparticles. The hybrid substrate not only showed excellent reproducibility and stability of the SERS signal, but also maintained the flexibility and transparency of the pristine SiNWP...
March 24, 2017: ACS Sensors
Ankur Anand, Chia-Rung Liu, Ai-Chuan Chou, Wan-Hsuan Hsu, Rajesh Kumar Ulaganathan, Yi-Cheng Lin, Chi-An Dai, Fan-Gang Tseng, Chien-Yuan Pan, Yit-Tsong Chen
The concentration gradient of K(+) across the cell membrane of a neuron determines its resting potential and cell excitability. During neurotransmission, the efflux of K(+) from the cell via various channels will not only decrease the intracellular K(+) content but also elevate the extracellular K(+) concentration. However, it is not clear to what extent this change could be. In this study, we developed a multiple-parallel-connected silicon nanowire field-effect transistor (SiNW-FET) modified with K(+)-specific DNA-aptamers (aptamer/SiNW-FET) for the real-time detection of the K(+) efflux from cultured cortical neurons...
January 27, 2017: ACS Sensors
Jagadish Ch Mahato, Debolina Das, Nasrin Banu, Biswarup Satpati, B N Dev
Self-organized growth of well-ordered endotaxial silicide nanowires (NWs) on clean Si(110) surfaces has been investigated by in-situ scanning tunneling microscopy (STM) and transmission electron microscopy (TEM). Co deposition on clean Si(110) reconstructed surfaces at ~ 600°C produces unidirectional CoSi¬2 NWs by reaction of cobalt with the hot silicon substrate. STM investigations reveal four types of distinct NWs, all growing along [1-10] in-plane direction except one type growing along in-plane [113] direction...
July 18, 2017: Nanotechnology
Dharmraj Kotekar-Patil, Binh-Minh Nguyen, Jinkyoung Yoo, Shadi A Dayeh, Sergey M Frolov
We study signatures of ballistic quantum transport of holes through Ge/Si core/shell nanowires at low temperatures. We observe Fabry-Perot interference patterns as well as conductance plateaus at integer multiples of 2e^2/h at zero magnetic field. Magnetic field evolution of these plateaus reveals relatively large effective Lande g-factors. Ballistic effects are observed in nanowires with silicon shell thicknesses of 1 - 3 nm, but not in bare germanium wires. These findings inform the future development of spin and topological quantum devices which rely on ballistic subband-resolved transport...
July 13, 2017: Nanotechnology
Mingkun Xu, Jimmy Wang, Zhaoguo Xue, Junzhuan Wang, Ping Feng, Linwei Yu, Jun Xu, Yi Shi, Kunji Chen, Pere Roca I Cabarrocas
High mobility, scalable and even transparent thin-film transistors (TFTs) are always being pursued in the field of large area electronics. While excimer laser-beam-scanning can crystallize amorphous Si (a-Si) into high mobility poly-Si, it is limited to small areas. We here demonstrate a robust nano-droplet-scanning strategy that converts an a-Si:H thin film directly into periodic poly-Si nano-channels, with the aid of well-coordinated indium droplets. This enables the robust batch-fabrication of high performance Fin-TFTs with a high hole mobility of >100 cm(2) V(-1) s(-1) and an excellent subthreshold swing of only 163 mV dec(-1), via a low temperature <350 °C thin film process...
July 27, 2017: Nanoscale
Christophe Brun, Pierre-Henri Elchinger, Guillaume Nonglaton, Cheikh Tidiane-Diagne, Raluca Tiron, Aurélie Thuaire, Didier Gasparutto, Xavier Baillin
Metallic conductive nanowires (NWs) with DNA bundle core are achieved, thanks to an original process relying on double-stranded DNA alignment and physical vapor deposition (PVD) metallization steps involving a silicon substrate. First, bundles of DNA are suspended with a repeatable process between 2 µm high parallel electrodes with separating gaps ranging from 800 nm to 2 µm. The process consists in the drop deposition of a DNA lambda-phage solution on the electrodes followed by a naturally evaporation step...
July 5, 2017: Small
Bi-Shen Lee, Ding-Zheng Lin, Ta-Jen Yen
We present a facile and cost-effective manner to fabricate a highly sensitive and stable surface enhanced Raman scattering (SERS) substrate. First, a silicon nanowire array (SiNWA) is tailored by metal-assisted chemical etching (MaCE) method as a scaffold of the desired SERS substrate. Next, with an oblique angle deposition (OAD) method, optimized gold nanoparticles (AuNPs) are successfully decorated on the surface of the SiNWA. These AuNPs enable a strong localized electric field, providing abundant hot spots to intensify the Raman signals from the targeting molecules...
July 4, 2017: Scientific Reports
Daria V Beznasyuk, Eric Robin, Martien Den Hertog, Julien Claudon, Moïra Hocevar
We report on the growth of axial InAs-on-GaAs nanowire heterostructures on silicon by molecular beam epitaxy using 20 nm diameter Au catalysts. First, the growth parameters of the GaAs nanowire segment were optimized to achieve a pure wurtzite crystal structure. Then, we developed a two-step growth procedure to enhance the yield of vertical InAs-on-GaAs nanowires. We achieved 90% of straight InAs-on-GaAs nanowires by further optimizing the growth parameters. We investigated the composition change at the interface by energy dispersive x-ray spectroscopy and the nanowire crystal structure by transmission electron microscopy...
July 3, 2017: Nanotechnology
Zhiyuan Sun, David N Seidman, Lincoln J Lauhon
Dopants modify the electronic properties of semiconductors, including their susceptibility to etching. In semiconductor nanowires doped during growth by the vapor-liquid-solid (VLS) process, it has been shown that nanofaceting of the liquid-solid growth interface influences strongly the radial distribution of dopants. Hence, the combination of facet-dependent doping and dopant selective etching provides a means to tune simultaneously the electronic properties and morphologies of nanowires. Using atom-probe tomography, we investigated the boron dopant distribution in Au catalyzed VLS grown silicon nanowires, which regularly kink between equivalent ⟨112⟩ directions...
June 30, 2017: Nano Letters
Arman Davtyan, Thilo Krause, Dominik Kriegner, Ali Al-Hassan, Danial Bahrami, Seyed Mohammad Mostafavi Kashani, Ryan B Lewis, Hanno Küpers, Abbes Tahraoui, Lutz Geelhaar, Michael Hanke, Steven John Leake, Otmar Loffeld, Ullrich Pietsch
Coherent X-ray diffraction imaging at symmetric hhh Bragg reflections was used to resolve the structure of GaAs/In0.15Ga0.85As/GaAs core-shell-shell nanowires grown on a silicon (111) substrate. Diffraction amplitudes in the vicinity of GaAs 111 and GaAs 333 reflections were used to reconstruct the lost phase information. It is demonstrated that the structure of the core-shell-shell nanowire can be identified by means of phase contrast. Interestingly, it is found that both scattered intensity in the (111) plane and the reconstructed scattering phase show an additional threefold symmetry superimposed with the shape function of the investigated hexagonal nanowires...
June 1, 2017: Journal of Applied Crystallography
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"