共查询到20条相似文献,搜索用时 967 毫秒
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采用溶液化学法实现了在Zn(NO3)2/C6H12N4混合溶液中ZnO纳米线在AZO薄膜修饰过衬底上生长。AZO薄膜由射频磁控溅射法制备,通过溅射时间和基底温度的变化改变薄膜形态,重点研究了不同薄膜形态对ZnO纳米线形貌和结构的影响,最终在溅射2h、基底温度250℃晶种上得到垂直于衬底、高度平行取向的ZnO纳米线阵列。在此基础上研究了不同形貌ZnO纳米线阵列的紫外光电导性能差异。结果表明,垂直生长的纳米线较倒伏纳米线紫外响应迅速,分析认为是紫外光照下曝光面积不同造成的。 相似文献
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采用无金属催化剂的简单热蒸发法,在Si(100)衬底上不同生长温度下成功地制备了高密度和大长径比的单晶ZnO纳米线。分别利用X射线衍射仪(XRD)、扫描电子显微镜(SEM-EDS)、透射电子显微镜(TEM)及荧光光谱仪表征样品的结构和发光性质。XRD和TEM研究表明,所制备的样品为沿C轴择优取向生长的单晶ZnO纳米线,具有六方纤锌矿结构。SEM和TEM研究表明,生长温度对ZnO纳米线的形貌及长径比的影响较大。当生长温度为700℃时,制备得到长径比为300(长度约为15μm,直径约为50nm)的ZnO纳米线。低于600℃时,形成花状ZnO纳米锥或 纳 米 棒。高 于700℃时,形 成 小 长 径 比 的ZnO纳米棒。此外,室温光致发光(PL)谱上出现一个强而尖锐的紫外发射峰以及一个弱而宽泛的蓝光发射峰。采用的热蒸发法制备ZnO纳米线基于气-固(VS)生长机理且该生长方法可用于大规模、低成本制备高纯度的单晶ZnO纳米材料。 相似文献
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采用无金属催化剂的简单热蒸发法,在Si(100)衬底上不同生长温度下成功地制备了高密度和大长径比的单晶ZnO纳米线。分别利用X射线衍射仪(XRD)、扫描电子显微镜(SEM-EDS)、透射电子显微镜(TEM)及荧光光谱仪表征样品的结构和发光性质。XRD和TEM研究表明,所制备的样品为沿c轴择优取向生长的单晶ZnO纳米线,具有六方纤锌矿结构。SEM和TEM研究表明,生长温度对ZnO纳米线的形貌及长径比的影响较大。当生长温度为700℃时,制备得到长径比为300(长度约为15μm,直径约为50nm)的ZnO纳米线;低于600℃时,形成花状ZnO纳米锥或纳米棒;高于700℃时,形成小长径比的ZnO纳米棒。此外,室温光致发光(PL)谱上出现一个强而尖锐的紫外发射峰以及一个弱而宽泛的蓝光发射峰。采用的热蒸发法制备ZnO纳米线基于气-固(VS)生长机理且该生长方法可用于大规模、低成本制备高纯度的单晶ZnO纳米材料。 相似文献
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Co^2+掺杂ZnO纳米线的制备与光学特性的研究 总被引:1,自引:0,他引:1
在十六烷基三甲基溴化铵表面活性剂辅助下,通过水热合成法制备了Co2 掺杂ZnO纳米线.纳米线的直径为100~160nm,长度约为10μm.纳米线沿(001)方向生长.Co2 掺杂ZnO纳米线紫外-可见(UV-vis)吸收光谱曲线,显示掺杂的ZnO纳米线在200~300nm波段之间都有很强的紫外吸收,在波长360~370nm处显示很好的激子吸收,与体相的激子吸收峰(373nm)相比产生了蓝移.纳米线分别在385、409、433、462和495nm波段表现出发光特性,简略的讨论了其发光机制. 相似文献
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以采用物理热蒸发法制备的纯ZnO纳米线和Ni掺杂ZnO纳米线为气敏基料,制备成旁热式气敏元件,用静态配气法对浓度为10^-4的甲烷气体进行了气敏性能的测试.结果表明Ni掺杂使ZnO纳米线对甲烷灵敏度提高了182%,响应时间和恢复时间分别缩短了3和2s.Ni的掺杂,在ZnO半导体禁带中引入新的复合中心,形成附加能级,提高了ZnO纳米线对甲烷的灵敏度. 相似文献
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ZnO nanowires were synthesized on Si substrates by a simple metal vapor deposition method without any catalysts. The initial growth and the growth mechanism of the ZnO nanowires were studied using scanning and transmission electron microscopy. We found that the ZnO nanowires grew on the Si substrate via a self-seeding vapor-solid mechanism. The growth process of the ZnO nanowires consisted of four steps: self-seeding, one-dimensional epitaxial growth of the nanowires on the seeds by a base-growth mode, further acceleration of nanowire growth with additional seeding, and active formation of the nanowires. 相似文献
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Bong Jun KwonKyung Moon Lee Hae-Young ShinJinwoong Kim Jinzhang LiuSeokhyun Yoon Soonil LeeY.H. Ahn Ji-Yong Park 《Materials Science and Engineering: B》2012,177(2):132-139
Vertically aligned arrays of ultralong ZnO nanowires were synthesized on SiO2 substrates with carbothermal vapor phase transport method with Au seeding layer. High density of vertically aligned ZnO nanowires with lengths from a few to ∼300 μm could be grown by controlling growth conditions. Supply of high concentration of Zn vapor and control of the ratio between Zn vapor and oxygen are found to have the most significant effects on the growth of long ZnO nanowires in the vapor-solid growth mechanism. The nanowires are of high crystalline quality as confirmed by various structural, compositional, and luminescent measurements. Luminescent and electrical properties of ZnO nanowires with different growth conditions were also investigated. 相似文献
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ZnO nanowires were site-selectively deposited on the catalytic gold-patterned substrates using a vapor transport process at low temperature. We observed that Au-Zn phase played an important role in initiating the ZnO nucleation, which was identified from the TEM observation of the interface between the substrate and ZnO nanowires. And then further growth of the nanowires on the ZnO surface was driven by the reaction of the Zn vapor and O2 gas in vapor-solid growth mode. Finally, it was concluded that the site-specific deposition of ZnO nanowires was ascribed to the vapor-liquid-solid mechanism of Au, Zn vapor, and Au-Zn phases at the initial stage of ZnO nucleation. 相似文献
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Cha SN Song BG Jang JE Jung JE Han IT Ha JH Hong JP Kang DJ Kim JM 《Nanotechnology》2008,19(23):235601
A novel synthesis and growth method achieving vertically aligned zinc oxide (ZnO) nanowires on a silicon dioxide (SiO(2)) coated silicon (Si) substrate is demonstrated. The growth direction of the ZnO nanowires is determined by the crystal structure of the ZnO seed layer, which is formed by the oxidation of a DC-sputtered Zn film. The [002] crystal direction of the seed layer is dominant under optimized thickness of the Zn film and thermal treatment. Vertically aligned ZnO nanowires on SiO(2) coated Si substrate are realized from the appropriately thick oxidized Zn seed layer by a vapor-solid growth mechanism by catalyst-free thermal chemical vapor deposition (CVD). These experimental results raise the possibility of using the nanowires as functional blocks for high-density integration systems and/or photonic applications. 相似文献
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Lee KY Kumar B Park HK Choi WM Choi JY Kim SW 《Journal of nanoscience and nanotechnology》2012,12(2):1551-1554
We report growth of the ZnO nanowires on graphene/SiO2/Si substrates using a chemical vapor deposition method. The length of nanowires varies from 1 microm to 10 microm with increasing the growth time from 30 min to 90 min. X-ray diffraction and high-resolution transmission electron microscopy investigations predict the high structural quality of the c-axis grown single crystalline ZnO nanowires. Temperature dependent photoluminescence spectra from the nanowires reveal excellent optical quality and excitonic behavior in the single crystalline ZnO nanowires. A well-resolved free exciton emission at 3.375 eV, indicates high crystalline quality nanowires and a strong PL peak at 3.370 eV is assigned to neutral-donor bound excitons (D0X). 相似文献
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Jeong Ho ShinJae Yong Song Young Heon KimSung Dong Kim Hyun Min Park 《Materials Letters》2012,66(1):106-109
ZnO nanowires were grown onto SnO2 film coated on Si substrate using a vapor transport method. Zn vapor was found to play important roles in reducing SnO2 and in being oxidized as a ZnO layer. The growth mechanism of ZnO nanowires was revealed to be a two-step process of Zn-SnO2 redox reaction and Sn catalyzed V-L-S (vapor-liquid-solid) growth; initially, Zn vapor atoms arriving at the SnO2 surface reduce the SnO2 to Sn and O atoms and diffuse into the SnO2 layer to form a ZnO layer. The reduced Sn atoms diffuse out of the SnO2 layer and are agglomerated to form Sn liquid droplets. Then, the Sn droplets on the surface of ZnO layer serve as a catalyst for the catalytic V-L-S growth of ZnO nanowires. 相似文献
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ZnO nanowires have been grown on polycrystalline Zn2GeO4:Mn substrates for the first time using a chemical vapor deposition method. Both Zn and ZnO sources were used to supply Zn vapor in the growth process of ZnO nanowires. The Zn2GeO4:Mn substrates were prepared using solid-state ceramic synthesis methods, and average grain sizes of ~1 μm were achieved. The nanowires of diameters in the range of 100–200 nm and length of ~30 μm were observed. In addition to nanowires, other morphologies of ZnO nanostructures, such as ZnO tetrapods, were observed when Zn powder was used as the source for the CVD growth. The results reveal that polycrystalline substrates are also promising as novel alternative substrates for growth of ZnO nanostructures. The as-synthesized ZnO nanowire/Zn2GeO4:Mn composites are being developed for future electroluminescent devices. 相似文献
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Controlling the growth of zinc oxide nanowires is necessary to optimize the performance of nanowire-based devices such as photovoltaic solar cells, nano-generators, or light-emitting diodes. With this in mind, we investigate the nucleation and growth mechanisms of ZnO nanowires grown by metalorganic vapor phase epitaxy either on O-polar ZnO or on sapphire substrates. Whatever the substrate, ZnO nanowires are Zn-polar, as demonstrated by convergent beam electron diffraction. For growth on O-polar ZnO substrate, the nanowires are found to sit on O-polar pyramids. As growth proceeds, the inversion domain boundary moves up in order to remain at the top of the O-polar pyramids. For growth on sapphire substrates, the nanowires may also originate from the sapphire/ZnO interface. The presence of atomic steps and the non-polar character of sapphire could be the cause of the Zn-polar crystal nucleation on sapphire, whereas it is proposed that the segregation of aluminum impurities could account for the nucleation of inverted domains for growth on O-polar ZnO. 相似文献
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Hun Soo Jang Bokyeong Son Hui Song Gun Young Jung Heung Cho Ko 《Journal of Materials Science》2014,49(23):8000-8009
In this study, we demonstrate a method for creating multi-length-scale ZnO nanowires in a controllable manner on diverse planar and curvilinear substrates by introducing immiscible liquid masking layers (LMLs) above and beneath a nutrient solution used in hydrothermal growth. The confinement of volatile reactants by the LMLs stabilizes the pH, which is an important parameter in determining the shape of the nanowires, to enable growth in a stable manner. The conformal wettability of the LMLs provides freedom in the choice of target substrates and allows for the possibility of mounting spatially moving stages without the use of a specially designed solid lid. Selective growth within the growth zone defined by the LMLs in a dynamic- and/or static-mode can create various types of ZnO nanowires with gradual or terraced length profiles in two- or three-dimensional geometries. For a device application, we developed cylindrical photodetectors with the configuration of Cr/ZnO seed/ZnO nanowires/poly(3-hexylthiophene-2,5-diyl)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) to show the ability to spatially modulate the photo-sensitivity by controlled hydrothermal growth of diverse length scales of ZnO nanowires using the LML method. 相似文献