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Carbon nanotubes (CNTs) have been extensively studied during the past two decades and Catalytic Chemical Vapour Deposition (CCVD) technique has been untiredly employed by researchers to produce CNTs of various crystallographic configurations. In this paper the material aspects carbon sources, catalysts and substrates with regard to CCVD synthesis of carbon nanotubes are reviewed in light of latest developments and understandings in the field. The role of these materials in synthesis of CNTs is explained keeping the upto date literature in view. Latest research reports and their findings are presented with regard to effects of growth control aspects such as temperature, vapour pressure and catalyst concentration on CNT formation. Besides recent understandings with regard to preferential growth of CNTs are also discussed. From this literature review it is found that carbon diffusibility and carbon solubility of any catalyst are two important factors in determining CNT nucleation and growth. Moreover, addition of catalyst species to any transition metal catalyst can improve the catalyst performance and addition of water, air, alcohol etc. during CCVD process can increase the activity and lifetime of the catalyst besides enhances the production of CNTs. 相似文献
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Sascha Hermann Ramona Ecke Stefan Schulz Thomas Gessner 《Microelectronic Engineering》2008,85(10):1979-1983
Our interest is the integration of carbon nanotubes (CNT) in electronic devices (IC, NEMS). In the scope of this work, we present a study on the preparation of the catalyst Ni particles from ultrathin films and the synthesis of carbon nanotubes by the chemical vapour deposition method. For the preparation, we use a cold-wall CVD reactor especially designed for handling samples up to a size of a 4” wafer. We show the influence of different process conditions like temperature, initial layer thickness of catalyst and substrate on particle formation characterized by scanning electron microscopy (SEM). We show that the optimization of process conditions in the catalyst preparation phase is constitutive for dense CNT films. Regarding the application of CNTs as electrical interconnects, we studied the arrangement of nanoparticles on Al and TiN supporting layer. Furthermore, we fabricated the first test structures for the selective growth of CNTs out of contact holes on a Cu/TiN metallization layer system.The growth of multi-walled nanotubes (MWNTs) was performed with thermal CVD with ethylene as a precursor gas and hydrogen as supporting gas mixed in a nitrogen gas flow. The effects of growth condition on the quality and morphology of the CNTs were characterized by scanning electron microscopy, transmission electron microscopy (TEM) and Raman spectroscopy. The influence of temperature, gas composition and substrate on CNT growth will be presented. We managed to grow dense CNTs even at temperatures as low as 500 °C. 相似文献
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采用射频等离子体增强化学气相沉积(RF-PECVD),以Fe作为催化剂,在Si基片上生长了碳纳米管(CNT),采用扫描电子显微镜(SEM),高分辨透射电子显微镜(HR TEM)以及显微Raman光谱等对制备的CNT的形貌及结构进行了表征.结果表明:700℃和800℃温度下生长的CNT均取向无序、弯曲缠结,由整齐排列的圆... 相似文献
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Savita P. Somani Prakash R. Somani A. Yoshida M. Tanemura S.P. Lau M. Umeno 《Solid-state electronics》2008,52(6):941-945
Vertically aligned carbon nanofibers (CNF) and multiwalled carbon nanotubes (MWCN) were synthesized from camphor by catalytic thermal chemical vapor deposition on Co and Co/Fe thin films (for CNF) and on silicon substrates using a mixture of camphor and ferrocene (for MWCN). CNF and MWCN were studied by scanning and transmission electron microscopy, visible Raman spectroscopy, X-ray diffraction in order to get insight into the microstructure and morphology of these materials. Field electron emission study indicates turn-on field of about 1.52, 2.3 and 4.3 V/μm for MWCN, Co/CNF and Co/Fe/CNF films, respectively; and threshold field of about 2.48, 3.1 and 6 V/μm, respectively. Our study indicates a better performance for field electron emission compared with some of the earlier published reports which might be due to higher aspect ratio, good graphitization and suitable density. 相似文献
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目前,碳纳米管(CNTs)中无定形碳含量的测定方法很多,但由于测试样品方法不完善和样品预处理的方式不同,导致测量结果有较大差别,实验的可重现性也不好。本文对一种新的测定多壁碳纳米管(MWCNTs)中无定形碳含量的方法进行了研究。该方法基于不同形态碳与CO2反应活性的差异,利用CO2柔性氧化法氧化CNTs,采用热重法(TG)测定CNTs中无定形碳含量。并且,结合拍摄CNTs高分辨电子显微(HRTEM)像,证实通过该方法可使粗品中CNTs相和无定形碳相得以区分,达到了对CNTs中无定形碳进行定量分析的目的。本文也讨论了TG测试过程中的各个影响因素。 相似文献
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本文分析研究了甲酸镍二水合物作为催化剂前驱体,多壁管为原料,采用氢电弧放电法制得的双壁碳纳米管样品中不同管壁数目碳纳米管的分布及双壁碳管直径分布,发现样品中单壁和双壁碳管占主要地位,双壁管的内径主要分布在1.67 nm~3.67 nm之间,外径主要分布在2.33 nm~4.33 nm之间.此外,精确测定了三个双壁碳纳米管的螺旋指数,分别为[(28,3)(29,17)],[(19,8)(29,6)]及[(23,15)(28,22)],其电学性能分别为[半导体性,金属性],[半导体性,半导体性]及[半导体性,金属性].同时,观察了在不同条件下的电子辐照效应.结果表明,经辐照碳管的最内层管壁先发生断裂,其形变速度逐渐变慢,单根碳管易依附于大块物质.在相同的辐照条件下,管壁数目越多碳管越稳定.当管壁数目相同时,直径小的管比直径大的管稳定.高加速电压能够加速碳管的变形. 相似文献
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CVD工艺制备碳纳米管阵列,二甲苯(C6H4(CH3)2)作为碳源气体,二茂铁(C10H10Fe)作为催化剂前驱体,反应温度为700~800℃,碳纳米管直径30~60nm,长度50~60μm。 相似文献
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本文选用不同基底和溶剂进行单壁碳纳米管(SWNTs)样品制备,采用原子力显微镜(atomic force microscope,AFM)观察进行表征和观测。结果表明,溶剂和基底对样品制备十分重要,会直接影响AFM观测效果。以去离子水为溶剂进行样品分散时,SWNTs在石英、硅片和云母三种基底上都出现了不同程度的聚积和重叠,影响观测效果。而采用乙醇为溶剂,在石英或云母为基底进行成像时,均可获得质量良好的图像。选择云母作为基底,可以大大减少基底处理时间,制样方便快速,并且能够获得理想的观测效果。 相似文献
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Herein, we report the functionalization of multiwalled carbon nanotubes (MWCNTs) using meta-Chloroperoxybenzoic acid (mCPBA) as an oxidizing agent. Epoxy groups are incorporated into the sidewall of MWCNTs and the prepared functionalized multiwalled carbon nanotubes (F-MWCNTs) were characterized using FT-IR spectroscopy, X-ray diffraction, Raman spectroscopy and UV–visible spectroscopy. Morphology of MWCNTs and F-MWCNTs was determined using Scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM results clearly indicated that the diameter of F-MWCNTs is increased by 120% as compared to neat MWCNTs. From UV–visible spectroscopy data, band gap of F-MWCNTs was calculated using Tauc equation and it was found to be 3.9 eV. Photo emission property of F-MWCNTs was analyzed using photoluminescence spectroscopy. F-MWCNTs showed nice emission in the visible region and it depended upon the excited wavelength. These functionalized carbon nanotubes could find use as tunable optoelectronic devices in future nanotechnology. 相似文献
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碳纳米管对Ni60激光熔覆层的耐蚀性影响 总被引:2,自引:0,他引:2
利用自动送粉激光熔覆技术,在A3钢表面进行了Ni60合金添加碳纳米管的激光熔覆实验,采用静态浸泡法对相同工艺条件下获得的纯Ni60熔覆层和碳纳米管/镍基熔覆层的耐腐蚀性进行研究,在光学显微镜下观察样品表面腐蚀形貌,并对碳纳米管/镍基熔覆层的腐蚀机理进行了分析.结果表明:当碳纳米管的含量为0.3 wt%时,碳纳米管/镍基激光熔覆层的耐腐蚀性能最好,与纯Ni60激光熔覆层相比,耐腐蚀性提高1倍多.碳纳米管/镍基激光熔覆层耐腐蚀的原因在于熔覆层保留的碳纳米管使熔覆层更加致密,隔离了腐蚀介质,促进了镍基合金的钝化,从而提高了熔覆层的耐蚀性;同时,熔覆层中保留下来的碳纳米管和被分解的碳纳米管与金属基体形成碳化物,作为增强相均匀弥散在熔覆层中,它们的存在阻止了腐蚀坑的长大,因而蚀坑较小,耐腐蚀性得到提高. 相似文献
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Multi-wall carbon nanotubes (MWCNTs), grown by catalytic chemical vapor deposition (CCVD) over Fe supported on alumina catalyst, using isobutane as feedstock, are dispersed in aqueous solutions of sodium dodecyl sulfate. Stable and highly photosensitive heterojunctions are developed by liquid-phase deposition of MWCNTs/surfactant mixtures on the top of n-doped monocrystalline silicon wafers. Electrical measurements performed in the dark and under broad-band visible light, show that the hybrid solar cells, despite their non-optimized design, have conversion energy efficiency of the order of 3%. 相似文献