Growth of Single Crystalline ZnO Nanotubes and Nanosquids

2007 ◽  
Vol 1057 ◽  
Author(s):  
Abhishek Prasad ◽  
Samuel Mensah ◽  
Jiesheng Wang ◽  
Archana Pandey ◽  
Yoke Khin Yap

ABSTRACTThe growth of ZnO nanotubes and nanosquids is obtained by conventional thermal chemical vapor deposition (CVD) without the use of catalysts or templates. Characterization of these ZnO nanostructures was conducted by X-ray powder diffraction (XRD), Field-emission scanning electron microscopy (FESEM), Raman spectroscopy, and photoluminescence (PL). Results indicate that these ZnO nanostructures maintain the crystalline structures of the bulk wurtzite ZnO crystals. Our results show that rapid cooling can be used to induce the formation of ZnO nanotubes and ZnO nanosquids. The self-assembly of these novel ZnO nanostructures are guided by the theory of nucleation and the vapor-solid crystal growth mechanism.

2004 ◽  
Vol 829 ◽  
Author(s):  
H. W. Seo ◽  
D. Wang ◽  
Y. Tzeng ◽  
N. Sathitsuksanoh ◽  
C. C. Tin ◽  
...  

ABSTRACTZinc oxide (ZnO) is an interesting material for short-wavelength optoelectronics due to its wide band gap. The nanostructures of ZnO are also intriguing since a variety of morphology can be obtained by employing different processing parameters. In our laboratory, ZnO nanonails were successfully synthesized at low temperature using a thermal chemical vapor deposition. The morphology of the sample was studied by using scanning electron microscopy. The shape of the nail head can be controlled from hexagon to quasi-circular shape. X-ray diffraction, Raman scattering, photoluminescence spectroscopy were also performed to analyze the ZnO nanonail. Photoluminescence spectroscopy suggested that the defects in the ZnO nanonail and nanobone are of different nature.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 471 ◽  
Author(s):  
Martha Claros ◽  
Milena Setka ◽  
Yecid P. Jimenez ◽  
Stella Vallejos

Non-modified (ZnO) and modified (Fe2O3@ZnO and CuO@ZnO) structured films are deposited via aerosol assisted chemical vapor deposition. The surface modification of ZnO with iron or copper oxides is achieved in a second aerosol assisted chemical vapor deposition step and the characterization of morphology, structure, and surface of these new structured films is discussed. X-ray photoelectron spectrometry and X-ray diffraction corroborate the formation of ZnO, Fe2O3, and CuO and the electron microscopy images show the morphological and crystalline characteristics of these structured films. Static water contact angle measurements for these structured films indicate hydrophobic behavior with the modified structures showing higher contact angles compared to the non-modified films. Overall, results show that the modification of ZnO with iron or copper oxides enhances the hydrophobic behavior of the surface, increasing the contact angle of the water drops at the non-modified ZnO structures from 122° to 135° and 145° for Fe2O3@ZnO and CuO@ZnO, respectively. This is attributed to the different surface properties of the films including the morphology and chemical composition.


2011 ◽  
Vol 1348 ◽  
Author(s):  
Jian Lin ◽  
Miroslav Penchev ◽  
Guoping Wang ◽  
Rajat K Paul ◽  
Jiebin Zhong ◽  
...  

ABSTRACTIn this work, we report the synthesis and characterization of three dimensional heterostructures graphene nanostructures (HGN) comprising continuous large area graphene layers and ZnO nanostructures, fabricated via chemical vapor deposition. Characterization of large area HGN demonstrates that it consists of 1-5 layers of graphene, and exhibits high optical transmittance and enhanced electrical conductivity. Electron microscopy investigation of the three dimensional heterostructures shows that the morphology of ZnO nanostructures is highly dependent on the growth temperature. It is observed that ordered crystalline ZnO nanostructures are preferably grown along the <0001> direction. Ultraviolet spectroscopy indicates that the CVD grown HGN layers has excellent optical properties. A combination of electrical and optical properties of graphene and ZnO building blocks in ZnO based HGN provides unique characteristics for opportunities in future optoelectronic devices.


2013 ◽  
Vol 645 ◽  
pp. 3-9
Author(s):  
Qian Zhang ◽  
Qiu Xiang Wang ◽  
Hong Zhou Dong ◽  
Li Feng Dong

In this paper, we have synt hesized exotic carbon fibers with branched spurs by a chemical vapor deposition method using nickel catalyst precursor at 600 °C. No catalyst particles were found at the base of the carbon spurs, suggesting that the ni ckel catalyst particles, which were decomposed from the nickel catalyst precursor, facilitated the growth of the carbon fibers but not the spurs. The formation of the spurs resulted from the fluctuation of the carbon source gas acetylene flow. The samples were characterized by field emission sc anning electron microscopy, transmission electron microscopy, and X-ray powder diffraction.


1996 ◽  
Vol 11 (12) ◽  
pp. 3017-3023 ◽  
Author(s):  
G. Cicala ◽  
G. Bruno ◽  
P. Capezzuto ◽  
P. Favia

X-ray photoelectron spectroscopy (XPS) coupled with Fourier transform infrared (FTIR) and optical transmission spectroscopy (OTS) has been used for the characterization of silicon-carbon alloys (a-Si1−xCx: H, F) deposited via plasma, by varying the CH4 amount in SiF4–CH4–H2 feeding mixture. XPS measurements have shown that carbon-rich a-Si1−xCx: H, F alloys include large amounts of fluorine (>11 at. %), which make the films susceptible to the air oxidation. In addition, the effect of the alloying partner carbon on the valence band (VB) and on the VB edge position of amorphous silicon is also described.


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