A simple process to fabricate chain-like carbon nanotube （CNT） films by microwave plasma-enhanced chemical vapor deposition （MPCVD） was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were gro...A simple process to fabricate chain-like carbon nanotube （CNT） films by microwave plasma-enhanced chemical vapor deposition （MPCVD） was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were ground with Fe-doped SiO2 powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10-5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm2 at the electric field of 3.0 V/μm are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.展开更多
New magnetic air-stable nanogranular Fe thin films of 10 ± 1.2 nm thickness were prepared onto silicon wafers at 150℃ under inert atmosphere by controlled Chemical Vapor Deposition (CVD) of triiron dodecacarbony...New magnetic air-stable nanogranular Fe thin films of 10 ± 1.2 nm thickness were prepared onto silicon wafers at 150℃ under inert atmosphere by controlled Chemical Vapor Deposition (CVD) of triiron dodecacarbonyl (Fe3(CO)12). These thin films, composed of sintered elemental Fe nanoparticles of 4.1 ± 0.7 nm diameter, are protected from air oxidation by a very thin carbon layer. The saturation magnetization of these thin Fe coatings was found to be close to that of bulk iron. The electrical resistivity behavior of the ferromagnetic thin films is similar to that of a semiconductor. In the present manuscript, these Fe thin coatings on Si wafers have been used as a catalyst for synthesizing crystalline carbon nanotubes (CNTs), by CVD using ethylene as a carbon precursor.展开更多
Carbon nanotube(CNT)yarns with adjustable diameters were manufactured by twisting CNT films with varied twists.Different from traditional CNT fibers,CNT yarns exhibited a larger diameter(423μm)and a higher tensile fo...Carbon nanotube(CNT)yarns with adjustable diameters were manufactured by twisting CNT films with varied twists.Different from traditional CNT fibers,CNT yarns exhibited a larger diameter(423μm)and a higher tensile force(1988 cN).The results showed that CNT yarns with the twist angle of 35°exhibited the highest conductivity(886 S/cm)and the highest tensile strain(35%).展开更多
基于网络状碳纳米管(carbon nanotube,CNT)薄膜制备了网络状碳纳米管薄膜场效应晶体管(carbon nanotube thin film field effect transistor,CNT-TFT),研究了温度为100~300 K时,CNT-TFT的电学特性,并对关键电学参数,如开态电流I_(on)、...基于网络状碳纳米管(carbon nanotube,CNT)薄膜制备了网络状碳纳米管薄膜场效应晶体管(carbon nanotube thin film field effect transistor,CNT-TFT),研究了温度为100~300 K时,CNT-TFT的电学特性,并对关键电学参数,如开态电流I_(on)、跨导G_(m)、阈值电压V_(th)和亚阈值摆幅S_(S)等,进行了深入分析。研究结果表明,随着温度的降低,G_(m)出现了下降,V_(th)向左漂移;在G_(m)和V_(th)共同作用下,I_(on)显著下降。通过对电学参数随温度演化机制的深入分析,发现器件G_(m)的降低不仅与CNT内的散射及CNT-金属接触电阻相关,而且与交叠的碳纳米管间的结电阻密切相关。同时,研究还表明,低温下,界面俘获中心对电子俘获概率的减小是引起器件V_(th)和S_(S)变化的主要因素。展开更多
文摘A simple process to fabricate chain-like carbon nanotube （CNT） films by microwave plasma-enhanced chemical vapor deposition （MPCVD） was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were ground with Fe-doped SiO2 powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10-5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm2 at the electric field of 3.0 V/μm are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.
文摘New magnetic air-stable nanogranular Fe thin films of 10 ± 1.2 nm thickness were prepared onto silicon wafers at 150℃ under inert atmosphere by controlled Chemical Vapor Deposition (CVD) of triiron dodecacarbonyl (Fe3(CO)12). These thin films, composed of sintered elemental Fe nanoparticles of 4.1 ± 0.7 nm diameter, are protected from air oxidation by a very thin carbon layer. The saturation magnetization of these thin Fe coatings was found to be close to that of bulk iron. The electrical resistivity behavior of the ferromagnetic thin films is similar to that of a semiconductor. In the present manuscript, these Fe thin coatings on Si wafers have been used as a catalyst for synthesizing crystalline carbon nanotubes (CNTs), by CVD using ethylene as a carbon precursor.
文摘Carbon nanotube(CNT)yarns with adjustable diameters were manufactured by twisting CNT films with varied twists.Different from traditional CNT fibers,CNT yarns exhibited a larger diameter(423μm)and a higher tensile force(1988 cN).The results showed that CNT yarns with the twist angle of 35°exhibited the highest conductivity(886 S/cm)and the highest tensile strain(35%).
文摘基于网络状碳纳米管(carbon nanotube,CNT)薄膜制备了网络状碳纳米管薄膜场效应晶体管(carbon nanotube thin film field effect transistor,CNT-TFT),研究了温度为100~300 K时,CNT-TFT的电学特性,并对关键电学参数,如开态电流I_(on)、跨导G_(m)、阈值电压V_(th)和亚阈值摆幅S_(S)等,进行了深入分析。研究结果表明,随着温度的降低,G_(m)出现了下降,V_(th)向左漂移;在G_(m)和V_(th)共同作用下,I_(on)显著下降。通过对电学参数随温度演化机制的深入分析,发现器件G_(m)的降低不仅与CNT内的散射及CNT-金属接触电阻相关,而且与交叠的碳纳米管间的结电阻密切相关。同时,研究还表明,低温下,界面俘获中心对电子俘获概率的减小是引起器件V_(th)和S_(S)变化的主要因素。
