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1.
The GaN nanowires were successfully synthesized on Si(111) substrates by ammoniating the Ga2O3/ZnO films at 900 °C. The structure and morphology of the as-prepared GaN nanowires were studied by X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), scanning electron microscopy (SEM) and field-emission transmission electron microscopy (FETEM). The results show that the single-crystal GaN nanowires have a hexagonal wurtzite structure with lengths of about several micrometers and diameters ranging from 30 nm to 120 nm, which are conducive to the application of nanodevices. Finally, the growth mechanism is also briefly discussed. 相似文献
2.
GaN nanowires were synthesized by ammoniating Ga2O3 films on Ti layers deposited on Si (111) substrates at 950 °C. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR) and high-resolution transmission electron microscopy (HRTEM). The XRD, FTIR and HRTEM studies showed that these nanowires were hexagonal GaN single crystals. SEM observation demonstrated that these GaN nanorods with diameters ranging from 50 nm to 100 nm and lengths up to several micrometers intervene with each other on the substrate. 相似文献
3.
The vertically well-aligned GaN nanowires on c-Al2O3 substrates were grown via a vapor-liquid-solid mechanism. X-ray diffraction indicated the GaN nanowires to have epitaxial and homogeneous in-plan alignment with the c-Al2O3 substrates and a strong preferred orientation along the c-axis. The GaN nanowires had a single-crystalline hexagonal structure and c-axis orientation, as confirmed by high resolution transmission electron microscopy. 相似文献
4.
Dongdong Zhang Huizhao Zhuang Haibo Sun Yuping Cao Yinglong Huang Zouping Wang Ying Wang Yongfu Guo 《Materials Letters》2009,63(12):978-981
GaN nanowires doped with Mg have been synthesized on Si (111) substrate through ammoniating Ga2O3 films doped with Mg under flowing ammonia atmosphere. The Mg-doped GaN nanowires were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL). The results demonstrate that the nanowires were single crystalline with hexagonal wurzite structure. The diameters of the nanowires ranged 20-30 nm and the lengths were about hundreds of micrometers. The intense PL peak at 359 nm showed a blueshift from the bulk band gap emission, attributed to Burstein-Moss effect. The growth mechanism of the crystalline GaN nanowires is discussed briefly. 相似文献
5.
《Journal of Experimental Nanoscience》2013,8(3):238-247
GaN nanowires are fabricated on Si substrates by ammoniating Ga2O3/NiCl2 thin films using chemical vapour deposition method. The influence of reaction temperature on microstructure, morphology and optical properties of GaN nanowires is characterised by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrophotometer, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and photoluminescence. The results demonstrate that the GaN nanowires are single crystalline and exhibit hexagonal wurtzite symmetry. The best crystalline quality was achieved for an reaction temperature of 1150°C for 15?min. The growth process follows vapour–liquid–solid mechanism and Ni plays an important role as the nucleation point and as a catalyst. 相似文献
6.
《Materials Letters》2007,61(19-20):4103-4106
Needle-shaped GaN nanowires have been synthesized on Si (111) substrate through ammoniating Ga2O3/MgO films under flowing ammonia atmosphere at the temperature of 950 °C. The as-synthesized GaN nanowires were characterized by X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM). The results demonstrate that these nanowires are hexagonal GaN and possess a smooth surface with an average diameter about 200 nm and a length ranging from 5 μm to 15 μm. In addition, the diameters of these nanowires diminish gradually. The growth mechanism of crystalline GaN nanowires is discussed briefly. 相似文献
7.
《Materials Letters》2006,60(25-26):3076-3078
GaN nanowires have been synthesized on Si(111) substrate through ammoniating Ga2O3/BN films under flowing ammonia atmosphere at the temperature of 900 °C. The as-synthesized GaN nanowires were characterized by X-ray diffraction (XRD), selected-area electron diffraction (SAED), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results demonstrated that the nanowires are hexagonal wurtzite GaN and possess a smooth surface with diameters ranging from 40 to 100 nm and lengths up to several tens of micrometers. The growth mechanism of crystalline GaN nanowires is discussed briefly. 相似文献
8.
Large-scale GaN nanowires were successfully synthesized through ammoniating Ga2O3/Pd films sputtered on the sapphire(001) substrates. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, photoluminescence and Raman spectrum were used to characterize the specimens. The results demonstrate that nanowires are single crystal with hexagonal wurtzite structure and have good optical properties. Raman scattering appears broadened and asymmetric compared with those of bulk GaN due to its polycrystalline nature. In addition, the growth mechanism of GaN nanowires is briefly discussed. 相似文献
9.
《Journal of Experimental Nanoscience》2013,8(2):174-182
Mg-doped GaN nanowires have been successfully synthesised on Si(1?1?1) substrates by magnetron sputtering through ammoniating Ga2O3/Au thin films, and the effect of ammoniating time on microstructure and morphology were analysed in detail. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy and photoluminescence spectrum were carried out to characterise the microstructure, morphology and optical properties of the GaN samples. The results demonstrate that the nanowires after ammonification at 900°C for 15?min are single crystal GaN with a hexagonal wurtzite structure and high crystalline quality, having the size of 50–80?nm in diameter, more than 10 microns in length and good emission properties. The growth direction of this nanowire is parallel to [0?0?1] direction of hexagonal unit cell. Ammoniating time has a great impact on the microstructure, morphology and optical properties of the GaN nanowires. 相似文献
10.
11.
We report the growth of nonpolar GaN epitaxial films on nearly lattice-matched LiGaO2 substrate by a chemical vapor deposition (CVD) method. The structural, morphological and optical properties of GaN films were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), atomic force microscopy, and photoluminescence (PL) measurements. We found that growth temperature plays an important role in the preparation of pure m-plane films by CVD method. Pure m-plane GaN was achieved by optimized growth condition. Epitaxial relationship was revealed by TEM study. The PL spectrum at room temperature has a strong near-band-edge emission at 3.41 eV and a weak yellow luminescence band. 相似文献
12.
Y. P. Cao F. Shi X. W. Xiu H. B. Sun Y. F. Guo W. J. Liu Chengshan Xue 《Inorganic Materials》2010,46(10):1096-1099
The synthesis of Tb-doped GaN nanowires on Si (111) substrates through ammoniating Ga2O3 films doped with Tb was investigated. X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope,
high-resolution transmission electron microscopy and photoluminescence were used to characterize the composition, structure,
morphology and optical properties of the products. The results show that the as-synthesized GaN nanowires doped with 3 at
% Tb are of single-crystalline hexagonal wurtzite structure. The nanowires have diameters ranging from 30 to 50 nm and the
lengths up to tens of micrometers. An f-f intra-atomic transition of rare earth at 545 nm corresponding to 5
D
4–7
F
5 of the Tb3+ and other two peaks related with doping are observed in PL spectrum, confirming the doping of Tb into GaN. The growth mechanism
of GaN nanowires was discussed briefly. 相似文献
13.
Chuanwei Cheng Guoyue Xu Haiqian Zhang Jieming Cao Peipei Jiao Xiaoxia Wang 《Materials Letters》2006,60(29-30):3561-3564
Single-crystal wurtzite ZnS nanowires have been synthesized via a facile solution route with polyethylene glycol-400 as inducing template at low temperature (170 °C). The as-prepared products have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive X-ray analysis (EDX). Raman and photoluminescence spectrum (PL) were used to investigate the optical properties of ZnS nanowires. The strong emission peak centered at 322 nm in PL spectrum could be attributed to the band to band transitions. 相似文献
14.
15.
Liu Q Liu H Zhu J Liang Y Xu Z Yin G Han M 《Journal of nanoscience and nanotechnology》2006,6(1):231-234
Silver nanowires with high aspect ratios of up to more than 60 were synthesized on a large scale by the redox reaction between silver nitrate and sodium diphenylamine sulfonate at room temperature and in the absence of surfactant and hard-template and seed. When the molar ratio of reductant sodium diphenylamine sulfonate and silver nitrate < or =1, most products were all the nanowires. When the molar ratio increases to 2:1, silver nanowires and nanobelts were concomitantly formed. The redox product N, N'-diphenylbenzidinedisulfonate and sodium diphenylamine sulfonate all play an important role in the formation of silver nanostructures. The structure, morphology, and composition of the silver nanowires were characterized by the X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray energy dispersive microanalysis (EDX), and UV-Vis spectroscopy respectively. High-resolution transmission microscopy (HRTEM) and selected area electron diffraction (SAED) reveal the single-crystal nature of the silver nanowires. 相似文献
16.
《Materials Letters》2005,59(2-3):289-292
Large-scale productions of highly oriented FeS2−x (x=0.09) nanowires have been achieved by a simple low-cost, low-temperature solvothermal process. The X-ray diffraction (XRD) pattern revealed that the nanowires crystallized with cubic pyrite phase. Scanning electron microscopic (SEM) observation showed bundles of oriented nanowires with very high aspect ratio. Transmission electron microscopic (TEM) observation showed the nanowires to be smooth and uniform throughout their length. High-resolution transmission electron microscopy (HRTEM) and electron diffraction pattern revealed the single-crystalline nature of the nanowires. 相似文献
17.
The growth of GaN nanowires from Ga and NH3 sources in the flow of Ar carrier gas using a chemical vapor deposition (CVD) system was systematically studied. The substrates used were Si(111) and Si(100). Fabricated nanowires were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). We investigated the influence of growth temperature, catalyst used, Ga amount, and the ratio of Ar and NH3 flow rates on the morphology and properties of GaN nanowires. We found that the best results were obtained for a growth temperature of 950 °C. Optimal catalysts were Au and metallic Ni, while the use of nickel nitrate was found to lead to formation of SiOx nanowire bunches in addition to GaN nanowires. For the optimal temperature and catalyst used, the influence of the Ga to N ratio on the nanowire growth was studied. It was found that different types of nanostructures are observed in relatively Ga-rich and in relatively N-rich conditions. Growth mechanisms of different types of nanowires, including the stacked-cone nanowires and the microscale structures formed by lateral growth under N-rich conditions, are discussed. 相似文献
18.
Wang X Li L Wang S Guo Q Zhang Z Qian Y 《Journal of nanoscience and nanotechnology》2006,6(7):2042-2045
Uniform single-crystalline bismuth sulfide nanowires were prepared via a convenient solvothermal route under mixed-solvent condition. The nanowires were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) spectrometry and UV-vis spectrophotometer. The growth mechanism of the one-dimensional nanostructures was discussed. The optical absorption band gap of the nanowires is about 1.7 eV, and the blue-shift phenomenon can be observed with respect of that of the bulk Bi2S3, which might bring in new types of applications. 相似文献
19.
Huizhao Zhuang Jie Wang Junlin Li Peng Xu Feng Shi 《Journal of Materials Science: Materials in Electronics》2011,22(7):765-770
Well-crystallized ZnO nanowires have been successfully synthesized on NiCl2-coated Si substrates via a carbon thermal reduction deposition process. The pre-deposited Ni nanoparticles by dipping the
substrates into NiCl2 solution can promote the formation of ZnO nuclei. The as-synthesized nanowires were characterized by X-ray diffraction (XRD),
scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy
(HRTEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectrum. The results demonstrate that the as-fabricated
nanowires with about 60 nm in diameter and several tens of micrometers in length are preferentially arranged along [0001]
direction with (0002) as the dominate surface. Room temperature PL spectrum illustrates that the ZnO nanowires exist a UV
emission peak and a green emission peak, and the peak centers locate at 387 and 510 nm. Finally, the growth mechanism of the
nanowires is briefly discussed. 相似文献
20.
Jinhua Chen Huizhao Zhuang Lixia Qin Hong Li Zhaozhu Yang Dongdong Zhang 《Materials Research Bulletin》2008,43(11):2974-2978
A novel rare earth metal seed was employed as the catalyst for the growth of GaN nanorods. Large-scale GaN nanorods were synthesized successfully through ammoniating Ga2O3/Tb films sputtered on Si(1 1 1) substrates. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy were used to characterize the structure, morphology, and composition of the samples. The results demonstrate that the nanorods are high-quality single-crystal GaN with hexagonal wurtzite structure. The growth mechanism of GaN nanorods is also discussed. 相似文献