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1.
Guodong Wei Weiping Qin Ryongjin Kim Guofeng Wang Peifen Zhu Daisheng Zhang Kezhi Zheng Lili Wang 《Applied Physics A: Materials Science & Processing》2009,96(2):521-527
By using a novel and low-cost microwave method, three-dimensional SiC networks have been synthesized in large-scale. The composition
and structural features of the product were characterized by X-ray diffraction, field emission scanning electron microscopy,
and transmission electron microscopy. The results show that the SiC networks consist of nanocable X-junction and Y-junction.
Some nanocables are composed of 3C–SiC multicore encapsulated in single amorphous SiO2 shell. The SiC networks emitted stable violet–blue light around 380 nm under 325-nm excitation. Compared to the emission
peak of the SiC networks after etched and the reported results of 3C–SiC nanowires, the emission peak of the SiC networks
shows significant blueshift. The origin of the photoluminescence for the SiC networks could be due to two possible reasons:
the central crystalline SiC nanowires and amorphous SiO2 shell. A two-step growth mechanism of the SiC networks was proposed based on the experimental characterizations. The successful
synthesis of SiC networks is an important step in the development of SiC-based electronic devices and circuits. 相似文献
2.
ZnO–CuO core–shell nanorods and CuO-nanoparticle–ZnO-nanorod integrated structures were synthesized for the first time by
a two-stage solution process. Scanning electron microscopy and high-resolution transmission electron microscopy show that
the diameter and the length of the nanorods are around 60 and 800 nm, respectively. The morphologies of outer CuO could be
varied from nanoparticles to nanoshells by adjusting the solvent and dipping processes of copper (II) nitrate solution. The
CuO nanoparticles are single-crystalline or highly textured structures with size of around 30 nm. The CuO shell with thickness
of around 10 nm is constructed of nanocrystals with sizes in the range of 3–10 nm embedded in an amorphous matrix. Room-temperature
cathodoluminescence measurements of the CuO–ZnO nanocomposites exhibit relatively sharp ultraviolet emissions at 380 nm as
well as broad green and yellow emissions at 500 and 585 nm. The p-CuO/n-ZnO one-dimensional nanocomposites are promising for
optoelectronic nanodevice applications. 相似文献
3.
Xiaohua Jia Huiqing Fan Xiangdong Lou Jiaqiang Xu 《Applied Physics A: Materials Science & Processing》2009,94(4):837-841
The CdSnO3 semiconducting oxide that can be used as a gas-sensitive material for detecting ethanol gas is reported in this paper. CdSnO3 nanoparticles were prepared by a chemical co-precipitation synthesis method, in which the preparation conditions were carefully
controlled. The n-type gas-sensing semiconductors were obtained from the as-synthesized powders calcined at 600°C for 1 h.
The phase and microstructure of the obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission electron
microscopy (TEM), and Brunauer–Emmett–Teller (BET) method with a gas adsorption analyzer. CdSnO3 has a small particle size range of 30–50 nm and a high surface area of 9.12 m2/g, and a uniformity global shape. The gas sensitivity and operating temperature, and selectivity of CdSnO3-based sensors were measured in detail. The gas sensors fabricated by CdSnO3 nanoparticles had good sensitivity and selectivity to vapor of C2H5OH when working temperature at 267°C, the value of gas sensitivity at 100 ppm of C2H5OH gas can reach 11.2 times. Furthermore, gas-sensing mechanism was studied by using chromatographic analysis. 相似文献
4.
W. Wang Z. Liu Y. Liu C. Xu C. Zheng G. Wang 《Applied Physics A: Materials Science & Processing》2003,76(3):417-420
Using a simple wet-chemical route, we synthesized CuO nanorods with diameters of ca. 5–15 nm and lengths of up to 400 nm.
The purity, crystallinity, morphology, structure features, and chemical composition of the as-prepared CuO nanorods were investigated
by powder X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron
spectroscopy, and Raman spectroscopy.
Received: 22 March 2002 / Accepted: 12 June 2002 / Published online: 28 October 2002
RID="*"
ID="*"Corresponding author. Fax: +86-25/359-5535, E-mail: wangqun@nju.edu.cn 相似文献
5.
Properties of reactively sputtered W–B–N thin film as a diffusion barrier for Cu metallization on Si
L. C. Leu D. P. Norton L. McElwee-White T. J. Anderson 《Applied Physics A: Materials Science & Processing》2009,94(3):691-695
Thin films of W–B–N (10 nm) have been evaluated as diffusion barriers for Cu interconnects. The amorphous W–B–N thin films
were prepared at room temperature via reactive magnetron sputtering using a W2B target at various N2/(Ar + N2) flow ratios. Cu diffusion tests were performed after in-situ deposition of 200 nm Cu. Thermal annealing of the barrier stacks
was carried out in vacuum at elevated temperatures for one hour. X-ray diffraction patterns, sheet resistance measurement,
cross-section transmission electron microscopy images, and energy-dispersive spectrometer scans on the samples annealed at
500°C revealed no Cu diffusion through the barrier. The results indicate that amorphous W–B–N is a promising low resistivity
diffusion barrier material for copper interconnects. 相似文献
6.
ZnO nanoparticles, nanowires, and nanowalls were synthesized rapidly on Si via thermal decomposition of zinc acetate by a
modified chemical vapor deposition at a low substrate temperature of 200–250°C for the first time. The diameters of the synthesized
nanoparticles and nanowires are around 100 and 30 nm, respectively, and the thickness of nanowalls is around 20 nm. High-resolution
transmission electron microscopy shows that the nanowires as well as nanowalls are single-crystalline, and the nanoparticles
are highly-textured poly-crystalline structures. Room-temperature photoluminescence spectra of the nanostructures show strong
ultraviolet emissions centered at 368–383 nm and weak violet emissions at around 425 nm, indicating good crystal quality.
The study provides a simple and efficient route to synthesize ZnO diverse nanostructures at low temperature. 相似文献
7.
Lyda La-Torre-Riveros Emely Abel-Tatis Adrián E. Méndez-Torres Donald A. Tryk Mark Prelas Carlos R. Cabrera 《Journal of nanoparticle research》2011,13(7):2997-3009
With the aim of developing dimensionally stable-supported catalysts for direct methanol fuel cell application, Pt and Pt–Ru
catalyst nanoparticles were deposited onto undoped and boron-doped diamond nanoparticles (BDDNPs) through a chemical reduction
route using sodium borohydride as a reducing agent. As-received commercial diamond nanoparticles (DNPs) were purified by refluxing
in aqueous nitric acid solution. Prompt gamma neutron activation analysis and transmission electron microscopy (TEM) techniques
were employed to characterize the as-received and purified DNPs. The purified diamond nanoparticulates, as well as the supported
Pt and Pt–Ru catalyst systems, were subjected to various physicochemical characterizations, such as scanning electron microscopy,
energy dispersive analysis, TEM, X-ray diffraction, inductively coupled plasma-mass spectrometry, X-ray photoelectron spectroscopy,
and infrared spectroscopy. Physicochemical characterization showed that the sizes of Pt and Pt–Ru particles were only a few
nanometers (2–5 nm), and they were homogeneously dispersed on the diamond surface (5–10 nm). The chemical reduction method
offers a simple route to prepare the well-dispersed Pt and Pt–Ru catalyst nanoparticulates on undoped and BDDNPs for their
possible employment as an advanced electrode material in direct methanol fuel cells. 相似文献
8.
Hong-Liang Wen Kai-Sheng Yao Jia Wei Zhi-Ming Zhou Andreas Kirschning 《Journal of nanoparticle research》2009,11(2):499-503
Polymer-supported nano-amorphous Ni–B particles have been prepared by an ion exchange/chemical reduction protocol. The products
were characterized by inductively coupled plasma spectroscopy (ICP), X-ray powder diffraction (XRD), scanning electron microscopy
(SEM), and transmission electron microscopy (TEM). The polymer-supported Ni–B particles prepared at low temperature are 60–70
nm in size with a Ni–B ratio of Ni19B10.The choice of temperature is a crucial factor affecting particle size. 相似文献
9.
N. Henningsen R. Rurali K. J. Franke I. Fernández-Torrente J. I. Pascual 《Applied Physics A: Materials Science & Processing》2008,91(2):241-246
We biosynthesized iron oxide nanoparticles with four different pH in the solution to see its influence in the oxides obtained.
This method allowed for generating aggregates of 1–10 nm, and under optimal conditions (pH=10) we could control the size in
the range of 1–4 nm. With the purpose to analyze the biosynthesized iron oxide clusters we employed electron transmission
microscopy techniques. Because the biosynthetic method with alfalfa has been used, the presence of the biomass, which is dense
and within which are contained the nanoparticles, makes their observation difficult. Using the HAADF (Z contrast) technique
it is possible to locate the nanoparticles, which are then characterized using EDS and HRTEM.
PACS 61.46.-w; 68.37.Lp; 81.07.-b; 81.16.Be 相似文献
10.
Structure, refractive-index dispersion and the optical absorption edge of chemically deposited ZnxCd(1-x)S thin films 总被引:2,自引:0,他引:2
A.M. Salem 《Applied Physics A: Materials Science & Processing》2002,74(2):205-211
Zinc cadmium sulfide, ZnxCd(1-x)S, thin films have been deposited by a simple and inexpensive chemical bath deposition method from an aqueous medium using
thiourea as a sulfide-ion source. The structure of the deposited films has been characterized by X-ray diffraction and transmission
electron microscopy. It was observed from X-ray diffraction that the as-deposited films were amorphous in nature. However
ZnxCd(1-x)S films annealed at 423 K for 1.5 h show a crystalline structure with a small scattering volume. The obtained results were
confirmed throughout the transmission electron microscopy and the corresponding electron-diffraction patterns. The optical
constants of ZnxCd(1-x)S films annealed at 423 K for 1.5 h in the compositional range 0≤x≤1 were estimated using transmission and reflection spectra
in the wavelength range 300–2500 nm. The band gap varies non-linearly with the value of x. The dependence of the refractive
index on the wavelength obeys the single-oscillation model, from which the dispersion parameters and the high-frequency dielectric
constant were determined. A graphical representation of the surface and volume energy-loss functions was also given.
Received: 23 February 2001 / Accepted: 26 February 2001 / Published online: 27 June 2001 相似文献
11.
Olaf Krüger Tim Wernicke Joachim Würfl Roland Hergenröder Günther Tränkle 《Applied Physics A: Materials Science & Processing》2008,93(1):85-91
The effects of direct UV laser processing on single crystal SiC in ambient air were investigated by cross-sectional transmission
electron microscopy, Auger electron spectroscopy, and measurements of the electrical resistance using the transfer length
method (TLM). Scanning electron microscopy was applied to study the morphology and dimensions of the laser-treated regions.
After laser processing using a nanosecond pulsed solid-state laser the debris consisting of silicon oxide was removed by etching
in buffered hydrofluoric acid. A layer of resolidified material remains at the surface indicating the thermal impact of the
laser process. The Si/C ratio is significantly disturbed at the surface of the resolidified layer and approaches unity in
a depth of several tens of nanometers. A privileged oxidation of carbon leaves elementary resolidified silicon at the surface,
where nanocrystalline silicon was detected. Oxygen and nitrogen were detected near the surface down to a depth of some tens
of nanometers. A conductive surface film is formed, which is attributed to the thermal impact causing the formation of the
silicon–rich surface layer and the incorporation of nitrogen as dopant. No indications for microcrack or defect formation
were found beneath the layer of resolidified material. 相似文献
12.
A series of stoichiometric and nonstoichiometric copper–chalcogenide nanocrystallines with different morphologies, e.g., extremely
high aspect ratio nanofibers (Cu9S8), tubular structure (Cu
x
S (x=∼1.86–1.96), nanorods (CuS, Cu31S16), platelets (β-CuSe, Cu3Se2), rope-like Cu3Se2, as well as spherical nanoparticles (Cu7Se4, Cu2−x
Se), have been successfully synthesized in 20 vol% water and 80 vol% organic solvents mixture under mild conditions. The products
were characterized by various techniques, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission
electron microscopy (TEM), electronic diffraction (ED), and high-resolution transmission electron microscopy (HRTEM). The
studies of the optical properties revealed that the copper chalcogenides have a wide absorption in the range of about 400–700 nm,
with accessional IR band. Systematic studies showed that the mixture of 20 vol% water and 80 vol% organic solvents played
a key role in controlling the copper chalcogenides with different morphologies and phases. 相似文献
13.
L.H. Shen X.F. Li J. Zhang Y.M. Ma F. Wang G. Peng Q.L. Cui G.T. Zou 《Applied Physics A: Materials Science & Processing》2006,84(1-2):73-75
High-density hexagonal aluminum nitride (h-AlN) nanowires were synthesized through the direct reaction of Al with nitrogen gas without catalyst and template using a direct arc discharge method. The as-grown AlN nanowires were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The h-AlN nanowires have a diameter in the range 20–70 nm and a length of several tens of micrometers. Vapor–solid growth mechanisms can be employed to explain the formation of the h-AlN nanowires. PACS 81.05.Ea; 81.10.Bk; 81.16.Dn; 68.65.-k; 81.16.-c 相似文献
14.
Carbon nitride nanocrystals were prepared using a pulsed laser induced liquid–solid interfacial reaction and transmission
electron microscopy, while high resolution electron microscopy characterized their morphology and structure. It is important
that the cubic-C3N4 phase was observed. The formation mechanism of the carbon nitride nanocrystals is also discussed.
Received: 23 May 2000 / Accepted: 26 May 2000 / Published online: 2 August 2000 相似文献
15.
Large-scale cadmium sulfide (CdS) nanorods with high quality were successfully synthesized by solvothermal method using ethylenediamine
(en) aqueous as solvent. The as-obtained product was investigated by X-ray diffractometer (XRD), high-resolution transmission
electron microscopy (HRTEM), field emission scanning electron microscopy (FE-SEM), ultraviolet–visible (UV–Vis) spectrum and
photoluminescence (PL) spectrum. The length and width of the CdS nanorods were in the range of 1–2 μm, 30–40 nm, respectively.
XRD analysis revealed that the crystal structure of the product was hexagonal phase. Photoluminescence measurement showed
that the nanobelts have two main emission bands around 470 and 560 nm, which should come from the higher-level transition
and the intrinsic transition, respectively. 相似文献
16.
Yusuf Atici 《Applied Physics A: Materials Science & Processing》1997,64(3):307-314
+ Si(100) and bare Si(100) wafers by low pressure chemical vapour deposition (LPCVD) at 230–280 °C. The films were investigated
by transmission electron microscopy (TEM). The cross-sectional TEM samples of W/Si(100) exhibited a fine scale interface roughness,
which was attributed to the surface preparation. Irregular W plug structures were observed depending on the predeposition
procedures. It was observed that an insufficient deposition of W films on the contact surface leads to the presence of aluminium
around and underneath the plugs. This was observed by energy dispersive X-ray spectrometry (EDX). A study, using conventional
electron diffraction, confirmed that no silicides formed at the interfaces of W-bare Si(l00) wafers.
Received: 16 December 1996/Accepted: 6 May 1997 相似文献
17.
G. A. Martínez-Castañón N. Niño-Martínez F. Martínez-Gutierrez J. R. Martínez-Mendoza Facundo Ruiz 《Journal of nanoparticle research》2008,10(8):1343-1348
Silver nanoparticles with different sizes (7, 29, and 89 nm mean values) were synthesized using gallic acid in an aqueous
chemical reduction method. The nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light
scattering (DLS), X-ray diffraction (XRD), and ultraviolet–visible (UV–Vis) absorption spectroscopy; the antibacterial activity
was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to
the National Committee for Clinical Laboratory Standards. From the microscopies studies (TEM) we observed that silver nanoparticles
have spherical (7 and 29 nm) and pseudospherical shape (89 nm) with a narrow size distribution. The sizes of the silver nanoparticles
were controlled by varying some experimental conditions. It was found that the antibacterial activity of the nanoparticles
varies when their size diminishes. 相似文献
18.
G. F. Iriarte 《Journal of nanoparticle research》2011,13(4):1737-1745
Artificial nanostructures (Samuelson et al., Physica E 21:560–567, 2004; Xia et al., Adv Mater 15:353–389, 2003) show promise for the organization of functional materials (Huck and Samuelson, Nanotechnology 14:NIL_5–NIL_8, 2003) to create nanoelectronic (Mizuta and Oda, Science 279:208–211, 2008) or nano-optical devices (Mazur et al.; Tanemura et al., Synthesis, Optical Properties and Functional Applications of ZnO
Nano-materials: A Review, 1–3:58–63, 2008). However, in most manufacturing recipes described so far, nanostructures are synthesized in solution and/or uncontrolled
deposition results in random arrangements; this makes it difficult to measure the properties of attached nanodevices or to
integrate them with conventionally fabricated microcircuitry. Here, we describe a fully CMOS compatible process technology
for mass manufacture of polysilicon nanowires by the CVD (chemical vapor deposition) method. The large scale production of
nanowires could successfully be synthesized on silicon (100) substrates. However, the method presented here can successfully
be employed with all technologically useful substrates with good adhesion for silicon such as SiO2, diamond-like carbon or III–V semiconductors. This opens up the possibility for the fabrication of strain-sensitive and defect-sensitive
optoelectronic devices on the optimum III–V substrate (Fonstad et al.). Finally, scanning electron microscopy (SEM) was used
to characterize the as-synthesized nanowires and energy-filtered transmission electron microscopy (EFTEM) and scanning transmission
electron microscopy (STEM) analysis were used to determine the nanowire composition. 相似文献
19.
J.K. Jian X.L. Chen T. Xu Y.P. Xu L. Dai M. He 《Applied Physics A: Materials Science & Processing》2002,75(6):695-697
SnO2 nanowires were synthesized using a direct gas reaction route and were characterized by X-ray powder diffraction (XRD), scanning
electron microscopy (SEM), selected-area electron diffraction (SAED), high-resolution transmission electron microscopy (HRTEM)
and Raman-scattering spectroscopy. XRD, SEM, SAED and HRTEM indicated that the products were tetragonal SnO2 nanowires with diameters of 10–50 nm. The nanowires were single crystal and solid inside. Dendritic nanowires were observed
for the first time. Three vibrational modes were observed in the Raman spectra of the samples.
Received: 7 January 2002 / Accepted: 11 April 2002 / Published online: 19 July 2002 相似文献
20.
A. Wadeasa S. L. Beegum S. Raja O. Nur M. Willander 《Applied Physics A: Materials Science & Processing》2009,95(3):807-812
We report a demonstration of heterojunction light emitting diode (LED) based on a hybrid n-ZnO-nanorod/p-polymer layered structure.
The ZnO was grown using the aqueous chemical growth (ACG) on top of the polymer(s) which were deposited on glass. The current–voltage
(I–V) behavior of the heterojunctions showed good rectifying diode characteristics. Room-temperature electroluminescence (EL)
spectra of the LEDs provided a broad emission band over a wide LED color range (430–650 nm), in which both zinc and oxygen
vacancy peaks are clearly detected. We present here luminescent devices based on the use of ZnO-nanorods in combination with
two different blended and multi-layered p-type polymers. Electroluminescence of the first batch of devices showed that white
bluish strong emission for the presently used polymers is clearly observed. We obtained a turn-on voltage of 3 V and break-down
voltage equal to −6 V for PVK-TFB blended device. The corresponding values for the NPD-PFO multilayer device were 4 V and
−14 V, respectively. The rectification factors were equal to 3 and 10 for the two devices, respectively. The films and devices
processed were characterized by scanning electron microscopy (SEM), DEKTAK 3ST Surface Profile, Semiconductor Parameter Analyzer,
photoluminescence (PL), and electroluminescence (EL). 相似文献