We demonstrate here a simple and effective (n,m)-selective growth of single-walled carbon nanotubes (SWCNTs) in an aerosol floating catalyst chemical vapor deposition (CVD) process by introducing certain amount ammonia (NH(3)). Chiralities produced the presence 500 ppm NH(3) at 880 °C are narrowly distributed around major semiconducting (13,12) nanotube with over 90% SWCNTs having large chiral angles range 20°-30°, nearly 50% 27°-29°. The developed synthesis enables chiral-selective high...

SiO(2) supported cobalt (Co) catalyst could be partially reduced and anchored by unreduced Co ions during a carbon monoxide (CO) chemical vapor deposition (CVD) process. This resulted in the formation of sub-nanometre metallic clusters catalyzing growth single-walled nanotubes (SWNTs) with narrow diameter distribution.

The diameter of single-walled carbon nanotubes (SWNTs) is an important characteristic to determine their electronic properties and direct further applications in electronics photonics. A demand currently exists for accurate rapid method evaluating the mean distribution bulk SWNTs. Here, we provide effective means quantifying SWNTs using optical absorption spectroscopy without a strict prior assumption on form distribution. Verification this assignment protocol based upon statistical analysis...

We present a novel floating catalyst synthesis route for individual, i.e. non-bundled, small diameter single-walled carbon nanotubes (SWCNTs) with narrow chiral angle distribution peaking at high chiralities near the armchair species. An ex situ spark discharge generator was used to form iron particles geometric number mean diameters of 3-4 nm and fed into laminar flow chemical vapour deposition reactor continuous long high-quality SWCNTs from ambient pressure monoxide. The intensity ratio...

The growth mechanism and influence of synthesis parameters on the properties single-walled carbon nanotubes (SWNTs) produced by ferrocene vapor decomposition in a monoxide atmosphere have been investigated detail combined study Raman UV−vis−NIR absorption spectroscopy transmission electron microscopy (TEM). CO2 plays an essential role selective etching small diameter purification SWNTs. This effect is beneficial to narrow distribution control average Increasing temperature results formation...

Functionalized 3D porous carbons comprising encased iron carbide species, derived from a MOF, display outstanding ORR performance in both acidic and alkaline solutions.

Carbon nanobuds (CNBs) represent an emerging nanostructure, in which fullerene molecules are covalently bonded to the outer surface of single-walled carbon nanotubes (SWNTs). The Raman spectra CNBs were systematically investigated and compared those SWNTs. recorded using a 514 nm laser evaluating temperature-dependent frequency shift range 27−475 °C. temperature coefficient G-mode was much larger than that Consequently, have lower thermal stability, is attributed fact fullerenes sidewall At...

We report the effect of plasma parameters on properties ultrathin Al2O3 films prepared by enhanced atomic layer deposition for moisture barrier applications. The were grown at 90 °C using trimethylaluminum and O2 as precursors. Plasma power, exposure time concentration are found to influence growth behavior, composition density films. power ≥ 100 W leads lower impurity levels higher mass densities ∼2.85 g·cm−3. optimum our process, a an 3 s, reveal good water vapor transmission rate 5 × 10−3...

Femtosecond four-wave-mixing (FWM) experiments of individual suspended semiconducting single-walled carbon nanotubes (SWCNTs) are presented. The chiral indices the tubes were determined by electron diffraction as (28,14) and (24,14) having diameters 2.90 2.61 nm, respectively. diameter character additionally confirmed resonance Raman measurements. FWM signal showed electronic response from SWCNTs. results demonstrate that ultrafast dynamics SWCNTs can be studied spectroscopies.

Laser hyperdoped silicon with high crystallinity in doped layer is obtained by method of femtosecond laser irradiation NF3/SF6 gas mixture. SIMS measurement indicates nitrogen and sulfur dopants are incorporated into the top about 300 nm at concentrations above 1019 cm−3, SAD Raman Spectrum results show that there approximately crystalline layer. The co-hyperdoped almost same as annealed sample 800 K prepared SF6. improvement attributed to nitrogen, which effectively on repairing defects...

Dimethylaluminum chloride (DMACl) is a cost-effective aluminium precursor alternative to conventional trimethylaluminium (TMA) for Atomic Layer Deposited (ALD) Al2O3. The DMACl water process shows better passivation after high temperature firing when compared with TMA process. However, low-temperature post-anneal its quality slightly worse than TMA. Here we show that mixed use of and precursors in the ALD results surface both 400 °C an 800 step. high-quality from low interface defect density...

Batch processing of aluminum nitride (AlN) by thermal atomic layer deposition (ALD) was studied at high temperatures 500–550 °C using chloride (AlCl3) and ammonia (NH3) as metal nitrogen precursors. The growth behavior, chemical composition, morphology, crystallinity, residual stress the AlN films were characterized ellipsometry, x-ray photoelectron spectroscopy, force microscopy, scanning electron diffraction, wafer curvature method, respectively. deposited 525 had a good batch thickness...

In this work, we report the successful growth of high-quality SiO2 films by low-temperature plasma-enhanced atomic layer deposition using an oxidant which is compatible with moisture/oxygen sensitive materials. The were grown at 90 °C CO2 and Bis(tertiary-butylamino)silane as process precursors. Growth, chemical composition, density, optical properties, residual stress investigated. having a saturated growth-per-cycle ~ 1.15 Å/cycle showed density 2.1 g/cm3, refractive index 1.46 wavelength...

Structural and photoluminescence studies were carried out on Eu-doped Y2O3-xSx thin films grown by atomic layer deposition at 300 °C. (CH3Cp)3Y, H2O, H2S used as yttrium, oxygen, sulfur precursors, respectively, while Eu(thd)3 was the europium precursor. The Eu oxidation state controlled during growth process following pulse with either a or O3 pulse. Eu(thd)3/O3 sequence led to emission above 550 nm, whereas Eu(thd)3/H2S resulted in below 500 nm.

We present an ab initio molecular dynamics study of the thermal stability and behaviors lattice misalignment structures (LMSs) in subsurface layers KH2PO4 (KDP) crystals. The dehydration process at atomic scale is observed LMS system, which same as that a perfect KDP crystal. However, paths entering are various. interesting result compared with crystal, many new appear even paths, more likely to happen system. This leads dramatic increase numbers for reasons given terms structural...

In this contribution, pulsed radio frequency (rf) glow discharge optical emission spectroscopy (GDOES) is used to investigate the film properties of SiO 2 deposited by plasma enhanced atomic layer deposition (PEALD), for example, chemical composition, structural and thickness. The total sputtering time until interface between Si substrate ≈13 s. main impurities in film, that is, H, C, N, are detected. It observed both C N intensities decrease with increasing power during thin film. higher...

In this article, a combined H 2 O thermal atomic layer deposition of Al 3 with in situ N plasma treatment process at 90 °C for encapsulation applications is reported. The effect parameters on the growth behavior and properties thin films, such as elemental composition, residual stress, moisture permeation barrier ability, density, roughness, investigated. Optimization exposure time gives films low impurity (≈3.8 at% hydrogen, ≈0.17 carbon, ≈0.51 nitrogen), high mass density (≈3.1 g cm −3 ),...

Atomic layer deposition (ALD) has been widely used in microelectromechanical systems (MEMS) due to its unique advantages, e.g. precise film thickness control, high uniformity and superb conformality. The understanding of ALD film's mechanical properties is important for MEMS device design fabrication. In this work, the studied thin films (Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O...

Abstract A new kind of N‐doped, hierarchically porous carbon catalyst (NHPC) derived from N‐rich space network polymers coupled with plenteous metal‐coordination sites was designed and controllably synthesized by exploiting nano‐SiO 2 as a hard‐template pyrolyzing strategy. The characterization result demonstrates that NHPC pyrolyzed at 900 o C exhibits lettuce‐like architecture high surface area (2112 m g −1 ). Remarkably, the porosity structure specific (SSA) can be accessibly tailored...