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以典型纳米器件一单壁碳纳米管场效应晶体管的装配制造为例,进行了规模化装配制造实验研究。采用浮动电势介电泳方法在每平方厘米装配上了六百对器件。实验结果表明本方法实现了规模化装配,且成功率较高。 相似文献
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用单壁碳纳米管(SWCNT)作为载体制备得到Pt,Pt—Fe,Pt—Co和Pt—Ni催化剂,并用循环伏安法和电化学阻抗谱法研究各催化剂对甲醇和乙醇氧化的电化学催化性能。对于甲醇和乙醇的氧化,Pt—Fe/SWCNT,Pt—Co/SWCNT和Pt—Ni/SWCNT电催化活性依次增强,抗中毒性能依次减弱。与Pt/SWCNT催... 相似文献
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流体排布与介电电泳结合排列组装碳纳米管 总被引:1,自引:0,他引:1
流体排布和介电电泳是碳纳米管生长后排列组装的两种方法.流体排布可实现基片上较大范围的碳纳米管定向排列,且流体剪切力作用可将弯曲的碳纳米管在一定程度上拉直,但利用流体难以实现在特定位置组装碳纳米管.而介电电泳通过电极上不均匀电场实现碳纳米管在电极间沿电场方向的定向定位排列组装,介电电泳的不足之处在于电泳力难以将弯曲的碳纳米管拉直.本研究结合这两种组装方法的优势,采用流体与介电电泳结合排列组装碳纳米管.通过选择流体流动和电泳参数,流体结合直流或带直流偏置的交流电泳实现了较好的碳纳米管排列组装.与介电电泳组装相比,结合流体能减少碳纳米管之间的粘连,起到梳理拉直的作用,并提高了组装效率;与流体排布相比,结合介电电泳实现了碳纳米管在指定位置的组装. 相似文献
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不同分散剂中碳纳米管的定向操控技术 总被引:2,自引:0,他引:2
利用介电电泳可以实现悬浮液中碳纳米管的定向操控.碳纳米管可以用表面活性剂和有机溶剂进行分散.对比了表面活性剂(十二烷基苯磺酸钠,黏滞系数为1.312mPa·s)和有机溶剂(二甲基甲酰胺,黏滞系数为0.802mPa·s),发现表面活性剂悬浮液中碳纳米管的溶解和分散效果好于有机溶剂中的溶解和分散效果,能实现单根分散.根据介电电泳原理,悬浮液中的碳纳米管在外加电场诱导下产生极化从而被驱动;分析了表面活性剂悬浮液和有机溶剂中碳纳米管的定向效果,发现有机溶剂中碳纳米管的定向效果好于表面活性剂悬浮液中的效果,表面活性剂悬浮液的黏滞系数大是阻碍外加电场有效定向操控碳纳米管的原因. 相似文献
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研究单壁碳纳米管杨氏模量的一种能量方法 总被引:2,自引:0,他引:2
本文利用能量方法研究了单壁碳纳米管(single-walled carbon nanotubes, SWCNT)的杨氏模量.文中,首先采用分子力学理论得出了受轴向载荷作用下单壁碳纳米管的总势能;然后通过总势能与相应薄圆柱壳的应变能比较,推导出了单壁碳纳米管杨氏模量的计算公式.另外,从一系列碳纳米管杨氏模量的计算发现,本文研究结果与现有研究结果比较一致. 相似文献
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利用共价连结和非共价修饰相结合的方法,成功地制备了基于单壁碳纳米管与铕、钆螯合物的复合体系(SWNT—Eu—Gd),并采用层层自组装的方法在单壁碳纳米管表面修饰多层高分子电解质作为隔离层,有效地克服了铕螯合物与单壁碳纳米管直接接触的荧光淬灭问题。SWNT—Eu—Gd复合体系除具有铕的特征荧光之外,还可以作为T1加权核磁共振造影剂,在纳米生物医学多模成像上具有潜在的应用。 相似文献
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以多壁碳纳米管(multi-walled carbon nanotubes,MWCNTs)和α-六噻吩(α-sexithiophene,α-6T)双层膜作为有源层,二氧化硅(SiO2)为绝缘层,钛/金(Ti/Au)作为电极,制备了沟道宽长比为640的有机薄膜晶体管(organic thin-film transistors,OTFT)气体传感器。测试了该传感器对痕量二氧化氮(NO2)气体的实时响应特性,并分析了NO2气体对OTFT传感器阈值电压、载流子迁移率等多参数的影响。研究结果表明,基于MWCNTs/α-6T的OTFT器件有较好的电学特性,载流子迁移率为3.0×10-2cm2/V·s;OTFT传感器对NO2气体具有较高的响应率,响应和恢复时间短,能检测(0.2~1)×10-6的痕量NO2气体,且具有良好的重复性;同时可以利用阈值电压和载流子迁移率等多参数来表征响应结果。形貌分析结果表明双层敏感膜的特殊形貌有利于提高器件的气敏性能。 相似文献
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利用塞贝克效应研制成功ZnO半导体气敏传感器。这种新型传感器能够输出0-100mV的直流电压,对于信号的放大与处理将十分方便。在实验中对20×10-6NO2气体进行检测,结果表明:传感器的输出电压(温差电动势),随着待测气体浓度而变化。因此,利用温差电效应制作气敏传感器是一条完全可行的新思路。 相似文献
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Jongyeol Baek Demin Yin Na Liu Inturu Omkaram Chulseung Jung Healin Im Seongin Hong Seung Min Kim Young Ki Hong Jaehyun Hur Youngki Yoon Sunkook Kim 《Nano Research》2017,10(6):1861-1871
Layered semiconductors with atomic thicknesses are becoming increasingly important as active elements in high-performance electronic devices owing to their high carrier mobilities,large surface-to-volume ratios,and rapid electrical responses to their surrounding environments.Here,we report the first implementation of a highly sensitive chemical-vapor-deposition-grown multilayer MoSe2 field-effect transistor (FET) in a NO2 gas sensor.This sensor exhibited ultra-high sensitivity (S =ca.1,907 for NO2 at 300 ppm),real-time response,and rapid on-off switching.The high sensitivity of our MoSe2 gas sensor is attributed to changes in the gap states near the valence band induced by the NO2 gas absorbed in the MoSe2,which leads to a significant increase in hole current in the off-state regime.Device modeling and quantum transport simulations revealed that the variation of gap states with NO2 concentration is the key mechanism in a MoSe2 FET-based NO2 gas sensor.This comprehensive study,which addresses material growth,device fabrication,characterization,and device simulations,not only indicates the utility of MoSe2 FETs for high-performance chemical sensors,but also establishes a fundamental understanding of how surface chemistry influences carrier transport in layered semiconductor devices. 相似文献
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Zhongwu Wang Shujing Guo Hongwei Li Bin Wang Yongtao Sun Zeyang Xu Xiaosong Chen Kunjie Wu Xiaotao Zhang Feifei Xing Liqiang Li Wenping Hu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(6)
The piezoresistive pressure sensor, a kind of widely investigated artificial device to transfer force stimuli to electrical signals, generally consists of one or more kinds of conducting materials. Here, a highly sensitive pressure sensor based on the semiconductor/conductor interface piezoresistive effect is successfully demonstrated by using organic transistor geometry. Because of the efficient combination of the piezoresistive effect and field‐effect modulation in a single sensor, this pressure sensor shows excellent performance, such as high sensitivity (514 kPa?1), low limit of detection, short response and recovery time, and robust stability. More importantly, the unique gate modulation effect in the transistor endows the sensor with an unparalleled ability—tunable sensitivity via bias conditions in a single sensor, which is of great significance for applications in complex pressure environments. The novel working principle and high performance represent significant progress in the field of pressure sensors. 相似文献
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Yaokun Pang Libo Chen Guofeng Hu Jianjun Luo Zhiwei Yang Chi Zhang Zhong Lin Wang 《Nano Research》2017,(11):3857-3864
Hydrogen detection with a high sensitivity is necessary for preventing potential explosions and fire.In this study,a novel ZnO tribotronic transistor is developed by coupling a ZnO field effect transistor (FET) and triboelectric nanogenerator in free-standing mode and is used as a sensor for hydrogen detection at room temperature.Tribotronic modulated performances of the hydrogen sensor are demonstrated by investigating its output characteristics at different sliding distances and hydrogen concentrations.By applying an external mechanical force to the device for sliding electrification,the detection sensitivity of the ZnO tribotronic transistor sensor is improved,with a significant enhancement achieved in output current by 62 times at 500 ppm hydrogen and 1 V bias voltage.This study demonstrates an extension of the applications of emerging tribotronics for gas detection and a prospective approach to improve the performance of the hydrogen sensor via human-interfacing. 相似文献
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Because of their excellent electrical and optical properties, carbon nanotubes have been regarded as extremely promising candidates for high-performance electronic and optoelectronic applications. However, effective and efficient distinction and separation of metallic and semiconducting single-walled carbon nanotubes are always challenges for their practical applications. Here we show that metallic and semiconducting single-walled carbon nanotubes on SiO(2) can have obviously different contrast in scanning electron microscopy due to their conductivity difference and thus can be effectively and efficiently identified. The correlation between conductivity and contrast difference has been confirmed by using voltage-contrast scanning electron microcopy, peak force tunneling atom force microscopy, and field effect transistor testing. This phenomenon can be understood via a proposed mechanism involving the e-beam-induced surface potential of insulators and the conductivity difference between metallic and semiconducting SWCNTs. This method demonstrates great promise to achieve rapid and large-scale distinguishing between metallic and semiconducting single-walled carbon nanotubes, adding a new function to conventional SEM. 相似文献
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为分析酸处理过程对石英晶振型碳纳米管(CNTs)有机(VOCs)气体传感器灵敏度的影响,制作了一种多壁碳纳米管(MWCNTs)石英晶振式VOCs传感器.发现酸处理可以明显提高传感器灵敏度,利用毛细凝聚原理与开尔文公式对上述实验现象进行了分析.另外,比较了传感器对不同有机气体(甲苯、乙醇和丙酮)的灵敏度,研究结果表明传感器灵敏度与气体饱和蒸汽压有关,同样,该实验现象可利用毛细凝聚原理与开尔文公式来解释. 相似文献
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采用水热法在硝酸锌(Zn(NO3)2·6H2O)与硝酸镁(Mg(NO3)2·6H2O)的生长液中制备了Mg掺杂的Mg/ZnO(MZO)纳米棒,其中生长液中Mg2+的物质的量浓度c(Mg2+)分别为0.05 mol/L、0.10 mol/L、0.25 mol/L和0.50 mol/L.利用场发射电子显微镜(FESEM)、X射线光电子能谱仪(XPS)、X射线衍射仪(XRD)、光致发光谱(PL)测试及场发射测试对所制备的MZO纳米棒的表面形貌、成分、晶体结构、光学性能及场发射性能进行了研究.结果表明:随着生长液中c(Mg2+)的增加,MZO纳米棒的直径逐渐减小、缺陷逐渐增加;且掺入的Mg含量与c(Mg2+)并不成正比关系;当生长液中的c(Mg2+)为0.10 mol/L时,所制备的MZO纳米棒的场发射性能最好,其开启场强为2.85 V/μm. 相似文献
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Karthigeyan A. Gupta R.P. Scharnagl K. Burgmair M. Zimmer M. Sulima T. Venkataraj S. Sharma S.K. Eisele I. 《IEEE sensors journal》2004,4(2):189-194
This paper presents the results on work function-based NO/sub 2/-sensing properties of iridium-oxide thin films at 130/spl deg/C. Films of 20-nm and 100-nm thickness were deposited on silicon substrates using dc sputtering followed by annealing in oxygen ambient. Sensitivity of these films to different concentrations of NO/sub 2/, H/sub 2/, CO, Cl/sub 2/, and NH/sub 3/ in synthetic air was measured using a Kelvin probe. It was observed that work function of 20-nm-thick iridium-oxide film changed by /spl sim/100 mV on exposure to 5-ppm NO/sub 2/ (German safety limit). Cross sensitivity to other gases (except NH/sub 3/) and interference of humidity was found to be negligibly small. The film was incorporated as a gate electrode in a hybrid suspended gate field effect transistor (HSGFET) structure to examine its suitability in FET-type sensors. The films were characterized using Rutherford backscattering spectroscopy, X-ray diffraction analysis, and scanning electron microscopy to determine their composition, phase, and surface morphology. The results suggest that iridium-oxide film is a promising material for the realization of a FET-based NO/sub 2/ sensor. 相似文献
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The electrode material for a gas sensor was prepared from electrospun carbon fibers. The electrode material was chemically activated to enlarge the gas adsorption sites, and carbon nanotubes (CNTs) were embedded into the polyacrylonitrile-based carbon fibers to enhance their electrical conductivity. TiO2 was used as an additive to promote NO gas degradation and to improve their response in NO gas sensing. The chemical activation process increased the specific surface area and pore volume of the carbon fibers to values in excess of 2000 m2/g and 1.0 ml/g, respectively. To investigate the photocatalytic effects of the TiO2 additive, NO gas sensing was conducted in the presence and absence of ultraviolet irradiation. The subsequent results indicate that the response of the sensor was improved due to the TiO2-photocatalyzed decomposition of NO gas and the subsequent adsorption of HNO2, NO2, and HNO3. The electrical resistance of the sensor was significantly reduced during NO gas sensing due to the electron hopping effect, and highly efficient gas adsorption was observed. In conclusion, a sensitive gas sensor electrode was realized by fabricating a porous material to increase the efficiency of gas adsorption, adding CNTs to improve its electrical conductivity and adding TiO2 photocatalysts to promote NO decomposition. 相似文献
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We fabricated a nanowire-based gas sensor using a simple method of growing SnO(2) nanowires bridging the gap between two pre-patterned Au catalysts, in which the electrical contacts to the nanowires are self-assembled during the synthesis of the nanowires. The gas sensing capability of this network-structured gas sensor was demonstrated using a diluted NO(2). The sensitivity, as a function of temperature, was highest at 200?°C and was determined to be 18 and 180 when the NO(2) concentration was 0.5 and 5?ppm, respectively. Our sensor showed higher sensitivity compared to different types of sensors including SnO(2) powder-based thin films, SnO(2) coating on carbon nanotubes or single/multiple SnO(2) nanobelts. The enhanced sensitivity was attributed to the additional modulation of the sensor resistance due to the potential barrier at nanowire/nanowire junctions as well as the surface depletion region of each nanowire. 相似文献