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ZnO纳米棒水热法制备及其发光性能 总被引:1,自引:0,他引:1
采用水热法在玻璃基底上成功制备出了ZnO纳米棒.用x射线衍射仪(xRD)和扫描电子显微镜(SEM)对ZnO纳米棒的晶体结构和表面形貌进行了表征,初步探讨了ZnO纳米棒的生长机理;同时对ZnO纳米棒的光致发光性能进行测量,分析了水热温度和反应时间对ZnO纳米棒光致发光性能的影响.结果表明:ZnO纳米棒呈现六方纤锌矿结构,具有沿(002)晶面择优生长特征;随着水热反应温度的升高,ZnO纳米棒的发光强度逐渐增强;随着反应时间的延长,ZnO纳米棒发光强度在1~3 h内增强,而在3~10 h反而减弱. 相似文献
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利用自主设计、组装的高压脉冲激光沉积(PLD)系统,研究了温度、靶材、催化剂厚度等生长参数对ZnO和Zn1-xMgxO纳米棒生长的影响,并对ZnO纳米棒的生长机理和Zn1-xMgxO纳米棒的光致发光性能进行了探讨.实验发现,当金膜催化剂厚度为2 nm、温度为925℃时,在单晶Si衬底上生长了直径均匀的ZnO纳米棒阵列,且具有明显的(002)择优生长取向.实验发现温度与催化剂厚度是影响ZnO纳米棒的直径和生长密度的重要因素.据此提出了ZnO纳米棒阵列的高压PLD生长过程应为气–液–固和气–固相结合的生长机制.通过在ZnO靶材中掺入氧化镁,获得了Zn1-xMgxO纳米线和纳米带结构,但生长无明显的择优取向.光致发光谱测量表明,镁掺杂明显增大了ZnO的带隙,但也在其禁带中引入了缺陷能级,导致可见发光明显增强. 相似文献
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使用低温水热法在Si衬底上生长ZnO纳米棒阵列.通过X射线衍射和扫描电子显微镜对ZnO纳米棒的结晶性和形貌进行观测.结果表明,六棱柱形ZnO纳米棒沿c轴方向的阵列性良好,且均匀致密的生长在衬底上.室温光致发光谱表明应用低温水热法可以得到光学性质良好的ZnO纳米棒阵列.使用同步辐射对ZnO纳米棒阵列的氧K带边进行X射线吸收近带边谱测量,研究了不同半径ZnO纳米棒阵列的局部电子结构及其半径对电子结构的影响.另外,对ZnO纳米棒及ZnO薄膜的局部电子结构进行了对比研究. 相似文献
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采用低温水溶液法, 在涂覆ZnO种子层的ITO基底上制备了高度取向的ZnO棒晶阵列, 考察了棒晶的生长过程以及生长液浓度、生长时间对薄膜形貌的影响. 用扫描电子显微镜(SEM),X射线衍射(XRD), 场发射扫描显微镜(FESEM)以及高分辨透射电镜(HRTEM)对ZnO纳米棒的结构和形貌进行了表征. 结果表明, ZnO薄膜的形貌强烈依赖于生长溶液的浓度和生长时间, ZnO棒是单晶, 属于六方纤锌矿结构, 具有沿(002)晶面择优生长的特征, 生长方式为层层台阶生长, 反应时间达到48h后, 通过二次生长形成特殊的板状晶. 相似文献
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以水热法生长ZnO纳米棒阵列为模板,利用液相沉积法成功制备了TiO2纳米管阵列,并系统研究了液相沉积液浓度和沉积时间对ZnO纳米棒的溶解情况,以及所制备TiO2纳米管阵列的场发射性能。实验结果表明:硼酸浓度越大、沉积时间越长,对ZnO纳米棒的溶解作用越明显,因而越不利于TiO2纳米管的制备。利用该种方法制备的TiO2纳米管长径比和致密性可通过ZnO纳米棒的水热生长条件来控制,本实验制备的TiO2纳米管具有优异的场发射性能,其开启场强为4.60 V/μm,场增强因子为10239。 相似文献
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采用气相法、液相法相结合的方法外延组装了一种形貌新颖的复杂ZnO分级纳米结构--"纳米毛刷".首先用热蒸发的方法制备了宽面为极性面的ZnO纳米带,然后采用化学溶液法,在强碱溶液中在ZnO纳米带的极性面上外延生长Zno纳米棒阵列,实现了ZnO分级纳米结构"由下而上"地外延组装.采用负离子配位多面体生长基元模型讨论了ZnO分级纳米结构的外延组装机理.这种ZnO分级结构的实现,可望作为ZnO纳米器件的原型材料构建新型光电器件. 相似文献
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Various electroless Ni-Co-P films were deposited on silicon substrates in electroless baths using sodium hypophosphite as reducing agent and nickel and cobalt sulfates as ion source at pH value of 9 and temperature from 55 to 85 °C. The effect of the atomic ratio of Co to Ni + Co in baths on the growth behavior of the electroless Ni-Co-P films was studied. The various electroless Ni-Co-P films were characterized by scanning electron microscopy for the morphology, transmission electron microscopy for the microstructure and thickness, and energy dispersion spectroscopy for the composition. The results showed that the growth rate of the electroless Ni-Co-P films is generally increased with increase of the bath temperature and is decreased with atomic ratio of Co to Ni + Co in baths. The reduction of the Co2+ ion is easier than the Ni2+ ion in various baths, except for the bath with 0.9 atomic ratio of Co to Co + Ni. 相似文献
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Jeun Jye Ong Oliver M. OReilly 《International Journal of Engineering Science》2004,42(19-20):2159-2174
Appropriate balance equations are formulated for a body whose geometry, mass and inertia vary due to surface growth. The distance between any two particles of the body is assumed to be fixed and hence several interesting simplifications of the balance laws occur. In particular, a set of ordinary differential equations for the attitude and position of the body are developed. The dynamics predicted by these equations for a body moving on an incline, and gathering mass as it does so, are discussed. 相似文献
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Unidirectional <100> potassium dihydrogen orthophosphate (KDP) single crystals were grown for the first time by Sankaranarayanan-Ramasamy (SR) method. The <100> oriented seed crystals were mounted at the bottom of the glass ampoules and the crystal of 15 mm diameter, 65 mm height were grown by SR method. The grown crystals were characterized by high-resolution X-ray diffraction (HRXRD), etching studies. The HRXRD analysis indicates that the crystalline perfection is excellent without having any very low angle internal structural grain boundaries. Dislocation density is less in SR grown KDP compared to conventional method grown KDP. 相似文献
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Weimin WANG Junming LIU Zhiguo LIULaboratory of Solid State Microstructures Nanjing University Nanjing China 《材料科学技术学报》2002,18(4)
A modified Monte-Carlo(MC) method to simulate the regular growth of binary eutectic alloys is presented. It is found that the growth rate has a linear dependence on the chemical potential difference between the solid and liquid; the relation between the lamellar spacing A and growth rate R accords well with the prediction of Jackson-Hunt(JH) theory unless the growth rate is very low. 相似文献
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A modified Monte-Carlo(MC) method to simulate the regular growth of binary eutectic alloys is presented.It is found that the growth rate has a linear dependence on the chemical potemtial difference between the solid and liquid ,the relation between the lamellar spacing λ and growth rate R accords well with the prediction of Jackson-Hunt(JH) theory unless the growth rate is very low. 相似文献
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Carbon nanotubes were electrodeposited in acetonitrile solution at room temperature using Cu, and Fe-Ni nanoparticles as nucleation sites on HF-etched Si(100) wafer substrate. The electrochemical behavior of the deposition was investigated by voltammetry and chronoamperometry techniques. In order to obtain the optimum growth condition, the deposition critical parameters including current density range, potential and time were studied and calculated. Carbon nanotubes with approximate external diameter of 40-100 nm were fabricated under potentiostatic condition and diffusion control at − 20 V in 4-6 h. The film crystallinity was investigated by means of X-ray diffraction and the tubes structure was revealed using scanning electron microscope and transmission electron microscope images. Raman spectroscopy was also employed to characterize the nanostructural features and single wall carbon nanotubes were detected. 相似文献
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Effect of growth temperature on structure and optical characters of NiO films fabricated by PA-MOCVD
H. Wang Guoguang WuX.P. Cai Y. ZhaoZ.F. Shi J. WangX.C. Xia X. DongB.L. Zhang Y. Ma G.T. Du 《Vacuum》2012,86(12):2044-2047
We report the effect of growth temperature on structure, optical and electrical properties of NiO films fabricated by Photo-assisted Metal Organic Chemical Vapor Deposition (PA-MOCVD). It is found that the crystal quality of the NiO films has been improved by increasing the growth temperature. When the temperature is low, the NiO film is composed of small and anomalous grains, whereas the film is composed of grains with a cubic shape following the NaCl-type structure when the temperature is higher. The samples marked A-D under the growth temperature of 510, 540, 570 and 600 °C have optical band gap values of 3.93 eV, 3.82 eV, 3.73 eV and 3.55 eV, respectively. Comparatively, the controllable electrical properties of the films can be achieved by the variation of crystal quality arises from the growth temperature. 相似文献
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Si nodules that appear in the metal electrodes of integrated circuits often reduce their reliability. The growth process of Si nodules generated on boro-phospho silicate glass (BPSG) in the Al-1 wt.% Si film electrode has been investigated. The Al-1 wt.% Si films sputter deposited on BPSG films were annealed at 723 K for 30 min according to the usual integrated circuit procedure. Scanning electron microscopy and atomic force microscopy observations revealed that the Si nodules seemed to precipitate along Al grain boundaries particularly on the BPSG film and their shape appeared pyramidal. To make clear the mechanism of the growth of the Si nodule on the BPSG film, the interface between the Si nodule and the BPSG film was investigated in detail by transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. As the result, it was found that there existed an amorphous silicon oxide region in the central part of the interface under the Si nodule. The amorphous silicon oxide is considered to be formed by diffusion of oxygen from the BPSG film to the Si nodule during the annealing. The amorphous silicon oxide may act as an embryo for the formation of the Si nodule and the migration of Si atoms dissolved in Al towards the embryo seems to enhance the growth of the Si nodule. 相似文献