共查询到19条相似文献,搜索用时 125 毫秒
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为了研究有机溶剂对化学合成法中生成的氧化铋纳米材料结构及场发射性能的影响,反应过程中,分别添加三个不同剂量的有机溶剂,获得三种产物。利用扫描电镜对其结构进行分析,并进行场发射性能测试,结果表明,线状的氧化铋纳米材料阴极阵列,开启电场最小,为2.6 V/μm,场增强因子最大,为2160,场发射性能最佳,手状结构的氧化铋纳米材料阴极阵列场发射次之,类手状结构最差,最后对有机溶剂对不同形貌产生的原因进行了分析。 相似文献
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Ag(TCNQ)纳米线的制备和场发射性能研究 总被引:1,自引:0,他引:1
采用气-液-固反应方法在硅片上制备了取向金属有机配合物Ag(TCNQ)纳米线.样品的XRD特征峰与Ag(TCNQ)相对应;SEM形貌显示纳米线几乎垂直基片生长,直径在50~300nm,长度在2~50μm.初步对其场发射性能进行了研究,所得Ag(TCNQ)纳米线的最低场发射开启电压约为1.5Vμm-1,最大发射电流密度约为0.03mAcm-2,此时对应的电场约为2.5Vpm-1.由测量所得I-Ⅴ曲线得到的FoWler-Nordheim(F-N)曲线近似为一条直线,说明样品具有场发射性能.重复实验表明,Ag(TCNQ)纳米线的场发射具有一定的稳定性.结合纳米线制备工艺,初步分析了场发射性能的影响因素. 相似文献
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首先在400℃的干燥空气(流量为500?sccm)及不同水汽流量(500、1500、3000、4000 sccm)等条件下分别热氧化铜片获得了系列垂直生长的氧化铜纳米线, 随后, 采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)研究了不同条件下所制备的氧化铜纳米线形貌、结构等性能, 并进一步研究了其场发射性能。研究结果表明: 水汽对氧化铜纳米线的密度及场发射性能影响较大, 在500 sccm空气流量条件下, 通入水汽(500 sccm)条件与未通入水汽条件生长得到的氧化铜纳米线相比, 其密度明显增大, 场发射性能提升, 其开启场强约为3.7 V/μm, 明显低于干燥空气中生长氧化铜纳米线的开启场强(6.5 V/μm); 此外, 制备得到的氧化铜纳米线的场发射性能随着通入水汽量增大出现先升高后降低的趋势, 并且, 在通入水汽流量为3000 sccm时, 获得最佳的氧化铜纳米线场发射性能, 其开启场强低至1.4 V/μm。 相似文献
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本文测量了垂直基底方向生长的硅纳米线阵列的场发射性质,并研究了引入金对其场发射性质的影响.引入金后,硅纳米线阵列在10 μA/cm2时的开启电场从4.7 V/μm降到了2.3 V/μm,并且根据Fowler-Nordheim曲线斜率的变化,估算出纳米线阵列的功函数从3.6 eV降到了2.2 eV. 相似文献
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薄膜场发射阴极中纳米线密度的理论优化 总被引:6,自引:0,他引:6
现在人们正在研究各种纳米线薄膜,因为它们很有可能成为新一代的场发射阴极而被应用于平面显示器等器件中,研究表明,除了纳米线的物理特性,薄膜的场发射特性也强烈地依赖于纳米阵列的几何构造。一方面,薄膜阴极的纳米线阵列密度要足够大,使得大量的场发射源能够产生,另一方面,过大的密度带来的屏蔽效应将严重削弱纳米线尖端的局域电场,在本文的参数下,利用Ansys软件计算出了纳米线的最佳间距-使得纳米之间的屏蔽效应可以忽略的最小距离-为纳米线高度的两倍。 相似文献
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现在人们正在研究各种纳米线薄膜 ,因为它们很有可能成为新一代的场发射阴极而被应用于平面显示器等器件中。研究表明 ,除了纳米线的物理特性 ,薄膜的场发射特性也强烈地依赖于纳米线阵列的几何构造。一方面 ,薄膜阴极的纳米线阵列密度要足够大 ,使得大量的场发射源能够产生。另一方面 ,过大的密度带来的屏蔽效应将严重削弱纳米线尖端的局域电场。在本文的参数下 ,利用Ansys软件计算出了纳米线的最佳间距———使得纳米线之间的屏蔽效应可以忽略的最小距离———为纳米线高度的两倍 相似文献
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Xu F Yu K Wang Q Shi M Zhang Q Bai W Li Q Zhu Z 《Journal of nanoscience and nanotechnology》2007,7(8):2774-2777
Hematite (alpha-Fe2O3) nanowires were synthesized by the thermal oxidation of Fe-Ni alloy grids at 900 degrees C. The effects of hydrogen (H2) plasmas on the morphology and field emission properties of hematite (alpha-Fe2O3) nanowires were investigated. Many nanocrystallites with sharp tips were found to be produced on the surface of the originally smooth nanowires after H2 plasmas treatment. Field emission measurements demonstrated that the treated alpha-Fe2O3 nanowires possessed much better performance with turn-on field of approximately 3.7 V/microm at 0.1 microA/cm2 of current density, compared with the as-grown samples. 相似文献
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《Materials Letters》2007,61(19-20):4152-4155
SnO2 nanowires were fabricated using a simple and economical method of rapid heating SnO2 and graphite powders at 850 °C in a flow of high-purity N2 as carrier gas. Research by using X-ray diffraction (XRD) indicates that SnO2 nanowires are primitive tetragonal in structure with the lattice constant a = b = 0.443 nm and c = 0.372 nm. Observations by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that SnO2 is of nanowire structure. The selected area electron diffraction (SAED) shows that the nanowires are perfect single crystal structure. The Fourier transform infrared (FT-IR) exhibits the difference of nanostructure materials and general materials. The field emission (FE) properties had also been studied. 相似文献
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Bi2O3-core/SnO2-shell nanowires have been prepared by using a two-step process: thermal evaporation of Bi2O3 powders and sputtering of SnO2. The crystalline nature of the Bi2O3-core/SnO2-shell nanowires has been revealed by high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). TEM analysis and X-ray diffraction (XRD) results indicate that the Bi2O3-core/SnO2-shell nanowires consist of pure tetragonal alpha-Bi2O3-phase momocrystalline cores and tetragonal SnO2-phase polycrystalline shells. The photoluminescence (PL) measurements show that Bi2O3 nanowires have a broad emission band centered at around 560 nm in the yellow-green region. On the other hand, the Bi2O3-core/SnO2-shell coaxial nanowires with the sputtering times of 4 and 8 min have a blue emission band centered at around 450 nm. In contrast, those with a sputtering time of 10 min have a broad emission band centered at approximately 550 nm again. The origin of this yellow-green emission from the core/shell nanowires, however, quite differs from that from Bi2O3 nanowires, i.e., it is not from the Bi2O3 cores but from the SnO2 shells. 相似文献
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A template-based heat-treatment method has been developed to convert metal nanowire arrays into arrays of metal-metal oxide core-shell nanowires and single-crystalline metal oxide nanotubes. This process is demonstrated by kinetically controlling the conversion of single-crystalline Bi nanowires to Bi-Bi(2)O(3) core-shell nanowires via a multistep, slow oxidation method, and then controlling their further conversion to a single-crystalline Bi(2)O(3) nanotube array via fast oxidation. This process can conveniently be extended to fabricate a free-standing, easily oxidized metal-metal oxide nanowire and metal oxide nanotube array, which may have future applications in nanoscale optics, electronics, and magnetics. 相似文献
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Hsueh TJ Hsu CL Chang SJ Lu CY Lin YR Chen IC 《Journal of nanoscience and nanotechnology》2007,7(3):1076-1079
Crabwise ZnO nanowires with an average length of 5 microm and an average diameter of 30 nm were selectively grown on ZnO:Ga/glass templates. Cathodoluminescence measurement indicated that the crystal quality of the crabwise ZnO nanowires was good. With an applied voltage of 120 V, the crabwise ZnO nanowire field emitters gave an emission current of 0.1 mA/cm2. Moreover, the field enhancement factor, beta, of the crabwise ZnO nanowires was approximately 980. 相似文献
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《Materials Letters》2007,61(8-9):1629-1632
Fe3O4 nanowires were successfully synthesized from ferrous chloride (FeCl2·4H2O) and diamine hydrate (H4N2·H2O) via the surfactant-assisted redox hydrothermal process induced by low magnetic field. The products as-prepared were characterized by X-ray diffraction, TEM and HRTEM. The mechanism for the formation of single-crystalline Fe3O4 nanowires was discussed based on the oriented growth of magnetic materials. 相似文献
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V. I. Maslov 《Technical Physics Letters》2001,27(2):153-154
An analysis of data on the experimental statistics of the field electron emission (FEE) from an oxide superconductor of the Bi2CaSr2Cu2O8 system reveals the multielectron tunneling effect. The spectral curves and statistical data obtained under various experimental conditions are considered, and possible mechanisms of the multiparticle tunneling are discussed. 相似文献
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利用物理热蒸发法制备大规模的蒲公英状的ZnO纳米锥,利用荧光光谱仪对ZnO纳米锥进行了光致发光性能测试.针对现有的丝网印刷碳纳米管(CNTs)薄膜需要各种后处理工艺后才能改善其场发射特性的问题,提出了一种不需任何后处理丝网印刷ZnO纳米锥的浆料配制工艺.用该工艺制备的丝网印刷ZnO纳米锥的场发射特性测试表明,ZnO纳米锥与制浆剂质量比为3∶5的薄膜的开启场强最低为2.25V/μm(电流密度为1μA/cm2),在4.6V/μm场强下,阳极荧光粉的发光点亮度高且分布均匀.说明该方法成本低,工艺简单,无需任何后处理,在ZnO纳米锥场发射显示器的制作中有很好的实际应用价值. 相似文献