共查询到19条相似文献,搜索用时 221 毫秒
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结合丝网印刷和过滤阴极真空电弧法、离子束溅射方法,在普通玻璃衬底上制备催化剂图案,采用低温热化学气相沉积法(CVD)生长碳纳米管/纤维(CNTs)薄膜.研究了不同种类催化剂对CNTs薄膜生长及其场发射的影响.结果表明,在a-C:Co,Ni-Cu和Cu三种催化剂上没有获得明显的CNTs,在外加电场小于4.4V/μm时没有观察到场发射;而在Ni-Fe及Ni-Cr两种催化剂上获得了大量的CNTs,并且表现出良好的场发射性能,开启电场为2.5V/μm,这种热CVD有简单、低温等优点,在CNTs场发射显示器的阴极制备中有潜在的应用价值. 相似文献
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LPCVD法制备碳纳米管薄膜及其场发射性能的研究 总被引:3,自引:0,他引:3
采用低压化学气相沉积法(LPCVD)在镍片上直接制备碳纳米管(CNTs)薄膜,系统地研究了生长温度(500~800℃)对碳纳米管薄膜形貌、结构及场发射性能的影响,并对此方法的生长机理进行了分析。当温度从500℃升高到650℃时,碳纳米管的生长速率随着温度升高而增大,而温度继续上升,速率则明显减小。利用扫描电镜(SEM)和拉曼光谱仪表征和检测了碳纳米管薄膜的形貌和结构。碳纳米管的管径、长度、一致性和晶化程度随温度都有明显的变化。同时还对碳纳米管薄膜的场发射特性进行了测试,对其场发射机理进行了深入地探讨,表明温度对碳纳米管的性能有很大影响,并存在最优化的温度条件。实验结果表明碳纳米管薄膜的形貌、结构及其场发射性能可通过生长温度进行一定范围的控制。 相似文献
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《中国光学与应用光学文摘》2006,(6)
O462.4 2006065340一种有效提高CNTs/CNFs阴极场发射性能的热处理方法=A heat-treatment process for effectively enhancing field emission characteristics of CNTs/CNFs cathodes[刊,中]/郭平生(华东师范大学物理系功能纳米材料和器件应用研究中心,上海(200062)),孙卓…//光电子·激光.—2006,17(6).—681-684报道了一种新的提高碳纳米管/碳纳米纤维(CNTs/ CNFs)丝网印刷阴极场发射性能的后处理方法。利用化学汽相沉积(CVD)方法制备的CNTs/CNFs作为阴极材料,采用丝网印刷工艺在玻璃基板上制备场发射阴极,在Hz和C_2 H_2混合气氛下500℃处理20 min,能有效提高其场发射性能,改善场发射显示器的发光均匀性。热处理后 相似文献
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碳纳米管场发射显示器的研究进展 总被引:8,自引:6,他引:8
碳纳米管因具有良好的电子发射特性而成为理想的场发射阴极材料,利用碳纳米管作阴极的场致发射平板显示器件的研究是目前显示技术领域的研究热点之一。报道了场发射显示器(FED)的结构及工作原理、阴极发射材料应具有的特点及碳纳米管在场发射领域中的应用情况。详细地论述了碳纳米管的场致发射特性,包括开启电场、发射电流密度、电流稳定性及发射点密度等,对国内外碳纳米管场发射显示器的发展现状及趋势作了回顾和展望,并对目前所面临的主要问题作了分析,同时提出了一些改进的思路。 相似文献
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《中国光学与应用光学文摘》2006,(5)
O484.12006054416LPCVD法制备碳纳米管薄膜及其场发射性能的研究=Deposition of carbon nanotubes fil mby LPCVDand relatedfield emission property[刊,中]/陈婷(华东师范大学纳米功能材料和器件应用研究中心.上海(200062)),孙卓…//光学学报.—2006,26(5).—777-782采用低压化学汽相沉积法(LPCVD)在镍片上直接制备碳纳米管(CNTs)薄膜,系统地研究了生长温度(500~800℃)对碳纳米管薄膜形貌、结构及场发射性能的影响,并对此方法的生长机理进行了分析。当温度从500℃升高到650℃时,碳纳米管的生长速率随着温度升高而增大,而温度继续… 相似文献
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采用丝网印刷工艺制作了碳纳米管(CNTs)薄膜阴极.经适当能量激光烧蚀后,相互粘连的CNTs随表面粘附有机物的蒸发而分散开,管间隙增加、屏蔽效应减小,使得场发射性能大幅度提高,开启场强降低、场倍增因子β增大.Raman光谱分析表明,随激光能量增加,CNTs表面缺陷增多,成为新的场发射点,对其β增大的贡献加强.相对于两电极结构,三电极中平栅极结构场发射性能经激光烧蚀有更显著的改善.这说明激光烧蚀是提高CNTs场发射性能的有效方法.
关键词:
碳纳米管薄膜
场发射
激光烧蚀
Raman光谱 相似文献
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研究了碳纳米管(CNT)场发射显示器(FED)三电极结构的平栅极结构,得到了进一步降低场致发射的开启电压和缩小动态调制电压范围的方法,同时也为相关的场发射安全操作提供了借鉴。实验表明:二极结构场发射调制电压范围较大,调制电压达上千伏,而在三电极的平栅极结构中通过调节阳极电压不仅可控制显示亮度,还对栅极调制电路有保护作用。适当升高阳极电压、适当缩短阴极和阳极之间的距离以及阴栅极经老化后可减小栅极调制电压, 同时还能有效的降低场致发射的动态调制电压的范围。这对新一代的显示器研制提供帮助。 相似文献
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在-180?℃—100?℃温度范围内研究了ZnO-Bi2O3二元、ZnO-Bi2O3-MnO三元以及商用ZnO压敏陶瓷的I-V特性.研究发现:二元试样电导由散射电导串联构成;三元试样电导由热电子发射电导混联构成;商用试样电导由热电子发射电导和隧道效应电导并联构成.对整个电流范围内的电导拟合表明:通过同一温度下电导分量同电流的关系,可以计算出该部分电导对应的非线性指数.在商用试样中,隧道电流产生的非线性指数为33,与实测值接近;该隧穿分量在小电流区也存在,且在低温下表现地更为明显.
关键词:
ZnO压敏陶瓷
I-V特性')" href="#">I-V特性
导电机理 相似文献
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用热处理方法对电子束蒸发制备的ZnO:Zn荧光薄膜分别进行400,600℃退火处理。采用X射线衍射、X射线光电子能谱、扫描电子显微镜、光致发光光谱等方法,表征了ZnO:Zn荧光薄膜的结构、成分、形貌、发光性能。在ZnO:Zn荧光薄膜的X射线衍射谱和扫描电子显微镜照片中,可以看出经退火处理后结晶状况大大改善,多晶结构趋于规则,晶粒更加均匀且膜层结构更加致密。在ZnO:Zn荧光薄膜的光致发光谱中,检测到490nm处发光峰,认为一价氧空位(VO)充当发光中心,且薄膜的光致发光强度受热处理温度的影响很大。实验表明随着退火温度的升高,薄膜的结晶程度提高,弥补了薄膜晶体表面的表面缺陷,薄膜的发光性能不断提高。 相似文献
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用化学气相沉积法制备了碳纳米管,进行了不同时间的球磨处理。用扫描电镜、拉曼光谱对其形貌和结构进行了表征。对不同球磨条件下的碳纳米管制备成阴极,进行了场致发射特性的测试。结果表明,高能球磨会对碳纳米管的形貌、结构及场致发射性能有明显的影响。球磨时间为0.5~1h时,可以使碳纳半管变短而均匀,且场致发射电性能与未处理时相近,即有低的阈值电场和高的发射电流密度,从而使发射时在阳极上产生的荧光点密度大大增加,发光均匀。但研磨时间过长会改变碳纳半管结构,使其非晶化或石墨化,导致其场致发射性能和显示效果变差。 相似文献
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Lili Wang Ting Chen Tao Feng Yiwei Chen Wenxiu Que Lifeng Lin Zhuo Sun 《Applied Physics A: Materials Science & Processing》2008,90(4):701-704
Growth of carbon nanotube (CNT) films with good field emission properties on glass is very important for low cost field emission
display (FED) applications. In addition to Ni, Co and Fe, Cu can be a good catalyst for CNT growth on glass, but due to diffusion
into SiO2 it is difficult to control the CNTs density and uniformity. In this paper, four metal barrier layers (W, Ni, Cr, Ti) were
deposited by dc magnetron sputtering on glass to reduce the Cu diffusion. As-grown CNT films showed various morphologies with
the use of different barrier metals. CNTs with uniform distribution and better crystallinity can be synthesized only on Ti/Cu
and W/Cu. Voltage current measurements indicate that better field emission properties of CNT films can be obtained on titanium
and tungsten barriered Cu, while chromium and nickel are not suitable barrier candidates for copper in CNT-FED applications
because of the reduced emission performance.
PACS 81.05.Uw; 61.46.Fg; 85.45.Db; 66.30.-h 相似文献
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Improve the field emission uniformity of carbon nanotubes treated by ball-milling process 总被引:1,自引:0,他引:1
Carbon nanotubes (CNTs) deposited by chemical vapor deposition (CVD) were treated by ball milling. The morphologies and field emission properties of the treated CNTs depending on milling time were studied. The emission turn-on field is increased, and the field emission current density is reduced, when the milling time increased from 0.5 to 3 h. The as-deposited long CNTs were cut to short CNTs (∼1 h) and micro-particles (>1 h) with increasing of the milling time. It is found that the optimized milling time is 0.5-1 h, the treated CNTs showed excellent field emission properties, such as low turn-on field, high emission current density and uniform luminescence spots distribution. 相似文献
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Controlled growth and field emission of vertically aligned AlN nanostructures with different morphologies
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The controllable growth of three different morphologies of AlN
nanostructures (nanorod, nanotip and nanocrater) arrays are
successfully realized by using chemical vapour deposition (CVD)
technology. All three nanostructures are of single crystal h-AlN
with a growth orientation of [001]. Their growth is attributed to
the vapour-liquid-solid (VLS) mechanism. To investigate the factors
affecting field emission (FE) properties of AlN nanostructures, we
compare their FE behaviours in several aspects. Experimental results
show that AlN nanocrater arrays possess the best FE properties, such
as a threshold field of 7.2~V/μm and an emission current
fluctuation lower than 4%. Moreover, the three AlN nanostructures
all have good field emission properties compared with a number of
other excellent cathode nanomaterials, which suggests that they are
future promising FE nanomaterials. 相似文献
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Selective plasma etching and hydrogen plasma treatment were introduced in turn to improve field emission characteristics of screen-printed carbon nanotubes (CNTs) cold cathode, which was prepared by using slurry of mixture of multi-wall CNTs, organic vehicles and inorganic binder, i.e. silicon dioxide sol. The results show that selective plasma etching process could effectively remove parts of surface inorganic vehicle (SiO2) layer and expose more smooth and clean CNTs on cathode surface, which could significantly decrease the operating field of CNTs cathode. There are some nanoparticles emerging on the out of CNTs wall after hydrogen plasma treatment, which are equivalent to increase field emission point of cathode. At the same time, these nanoparticles can increase the local electric field of CNTs, which can decrease operating voltage of CNTs cathode and improve uniformity field emission. 相似文献