用水热法制备超疏水性ZnO纳米棒薄膜

采用简单的水热法制备了超疏水性ZnO纳米棒薄膜,在用磁控溅射在Si(111)衬底上生长一层ZnO籽晶层的基础上,利用水热法制备了空间取向一致的ZnO纳米棒阵列,经修饰后由亲水性转变为超疏水性.用扫描电子显微镜、X射线衍射对样品表面和结构特征进行了表征,用接触角测量仪测出水滴在ZnO纳米棒薄膜表面的接触角为(160±1)°,滚动角为5°.     

偏压对磁控溅射ZnO薄膜的成核机制及表面形貌演化动力学的影响

利用反应射频磁控溅射技术,通过对基体施加负偏压溅射ZnO薄膜,探讨了固定偏压下ZnO薄膜的表面形貌随沉积时间的演化以及不同偏压对ZnO薄膜表面形貌的影响. 研究结果表明,在-100V的偏压下,随着沉积时间的增加,ZnO薄膜的表面岛尺寸不断减小,密度逐渐变大. ZnO在基片表面成核过程中的本征缺陷成核阶段和轰击缺陷成核阶段的生长指数分别为(0.45±0.03)和(0.22±0.04),低速率成核过程基本消失;随着偏压增大,表面岛的尺寸变大,表面起伏增加. 偏压不但可以改变ZnO薄膜的成核和生长过程,而且影响薄膜的晶体取向.     

蒲草型ZnO微纳结构的制备及其润湿性研究

以较高浓度的HF调控硝酸锌和六亚甲基四胺体系中ZnO的微观形貌,发现随着HF用量的增加,ZnO继发生短棒型、花型变化后最终变为蒲草型微纳结构;其形貌和润湿性用SEM和视频接触角测量仪进行表征。ZnO薄膜形貌的变化导致其润湿性发生相应变化,而且经紫外光照射处理后,蒲草型ZnO表面润湿性可以发生从疏水到超亲水的转变(CA~0°);黑暗放置7d左右,可以回到原来的疏水状态,而且可以反复多次。     

氧化锌超疏水薄膜的制备及其耐久性

为了提高氧化锌(ZnO)纳米疏水膜层在实际应用中的耐久性能,采用水热法在铝基底表面制备出微纳米结构的ZnO超疏水薄膜,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和接触角测量仪对所得ZnO薄膜的成分、微观结构及润湿性能进行分析;利用UMT摩擦磨损试验机对薄膜的摩擦性能和机械疏水耐久度进行研究;并用CHI660E电化学工作站对超疏水试样在海水中的耐腐蚀性能进行测量分析。结果表明:制备的微纳米结构ZnO薄膜具有超疏水性,在未经低表面能物质改性的情况下,对水的静态接触角高达152°,滚动角仅为2°;摩擦磨损测试表明该薄膜在经过2 400磨损周期后仍能保持较高的静态接触角;电化学阻抗谱和Tafel曲线测试表明,该薄膜的确降低了铝在海水中的腐蚀速率,缓蚀率高达93.8%。     

太阳电池用绒面结构ZnO-TCO薄膜及光管理研究进展

主要阐述了近年来薄膜太阳电池用绒面结构氧化锌(ZnO)透明导电氧化物(Transparent conductive oxides,TCO)薄膜以及光管理设计方面的研究进展。主要包括溅射湿法刻蚀技术、等离子体刻蚀玻璃衬底技术、等离子体处理修饰ZnO薄膜表面技术、修饰层改善ZnO薄膜表面技术、梯度杂质掺杂技术、复合特征尺寸生长设计以及直接生长绒面结构ZnO薄膜技术和宽光谱ZnO薄膜生长设计等。此外,对薄膜太阳电池中的先进光管理(Light management)结构设计及新材料应用进行了探讨和展望。     

ZnO纳米棒阵列和薄膜的同步外延生长及其光电化学性能

使用化学气相沉积法在a面蓝宝石衬底上同步外延生长氧化锌(ZnO)竖直纳米棒阵列和薄膜,研究了阵列和薄膜的光电化学性能。结果表明,纳米结构中的竖直单晶纳米棒有六棱柱形和圆柱形,其底部ZnO薄膜使竖直纳米棒互相联通。与ZnO纳米薄膜的比较表明,这种纳米结构具有优异的光电化学性能,其入射光电流效率是ZnO纳米薄膜的2.4倍;光能转化效率是ZnO纳米薄膜的5倍。这种纳米结构优异的光电化学性能,可归因于其高表面积-体积比以及其底部薄膜提供的载流子传输通道。本文分析了这种纳米结构的生长过程,提出了协同生长机理：Au液化吸收气氛中的Zn原子生成合金,合金液滴过饱和后ZnO开始成核,随后在衬底表面生成了ZnO薄膜。同时,还发生了Zn自催化的气-固(VS)生长和Au催化的气-液-固(VLS)生长,分别生成六棱柱纳米棒和圆柱形纳米棒,制备出底部由薄膜连接的竖直纳米棒阵列。     

IL-ZnO超疏水材料的制备及其稳定性研究

描述了新型[C12mim]Br-ZnO超疏水材料的制备及其紫外光(UV)照射下稳定性研究。首先将ZnO纳米薄膜沉积在玻璃基底表面,然后覆盖[C12mim]Br修饰层。IL-ZnO的形貌用SEM表征,其疏水性用接触角仪表征。研究表明,在蒲草型ZnO纳米材料表面覆盖[C12mim]Br后,获得超疏水,接触角(CA)可高达151.7±3°。用紫外光照射,可以实现光诱导的润湿性转化。用紫外光连续照射24h,黑暗放置一段时间后,接触角可回复到150±5°。表明离子液体做修饰层可以实现ZnO超疏水薄膜的稳定性。     

微纳分级结构ZnO-氟碳树脂超疏水表面的制备研究

超疏水表面具有特殊的微纳分级结构和自清洁、防污染等优异性能,国内外对其有着广泛的研究和应用。利用硝酸锌和氢氧化钾共沉淀的方法制备出海胆型微-纳分级结构的氧化锌(ZnO)粒子,然后用氟碳树脂衍生物对其进行疏水化接枝改性,最终制备了超疏水表面。利用X射线衍射仪对制备的产物进行物相分析,利用扫描电镜和动/静态接触角分析仪表征ZnO的微观形貌及疏水表面的接触角。结果表明,微纳分级结构的ZnO粒子经氟碳树脂改性后具有优异的疏水性能,所制备的疏水表面的水静态接触角能够达到(156±1)°,接触角滞后低至3°。该方法简单易行,适合工业化生产。     

ZnO纳米材料改性油漆涂层的制备及其浸润性的研究

采用水浴法生长出蒲公英状的纳米ZnO材料,并将其与油漆混合,制备出改良油漆涂层.分别用场发射扫描电子显微镜(FE-SEM)和接触角测量仪对其表面形貌和浸润性进行了表征.实验结果表明,加入ZnO材料后,不仅增加了油漆涂层的表面粗糙度,油漆涂层的疏水性能也得到显著改善,水滴在油漆涂层上的接触角由改良前的95°增加到改良后的...     

衬底温度对ZnO薄膜生长过程及微观结构的影响研究

以醋酸锌水溶液为前驱体,采用改进的超声喷雾热解法在Si(100)衬底上沉积ZnO薄膜,以X射线衍射(XRD)、扫描电镜(SEM)等手段分析所得ZnO薄膜的晶体结构和微观形貌,着重考察了衬底温度对ZnO薄膜生长过程及微观结构的影响.结果表明,在衬底温度为500℃下所得ZnO薄膜表面均匀光滑,属六方纤锌矿结构,且沿c轴择优生长,晶粒尺寸的为40～50nm;衬底温度对ZnO薄膜生长过程影响显著,随衬底温度的升高,薄膜生长速率存在一极限值,且ZnO薄膜的c轴取向趋势增强,晶粒尺寸得到细化.     

Structural and photoluminescence characterization of vertically aligned multiwalled carbon nanotubes coated with ZnO by magnetron sputtering

Zinc oxide (ZnO) nanostructures are very attractive in various optoelectronic applications such as light emitting devices. A fabrication process of these ZnO nanostructures which gives a good crystalline quality and being compatible with that of micro-fabrication has significant importance for practical application. In this work ZnO films with different thicknesses were deposited by RF-sputtering on vertically aligned multiwalled carbon nanotube (MWCNTs) template in order to obtain ZnO nanorods. The obtained hybrid structures (ZnO/MWCNTs) were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and time resolved photoluminescence spectroscopy (PL). Results show that the ZnO/MWCNTs have a nanorod structure like morphology with a good crystalline quality of the deposited ZnO on the MWCNTs. PL measurements reveal an enhancement of the band edge signal of ZnO/MWCNTs which is three times of magnitude higher compared to the ZnO film deposited on silicon. Moreover, the intensity enhancement varies as function of the ZnO thickness. Such hybrid structures are promising for optoelectronic application, such as blue-violet sources.     

Structure and physical properties of undoped ZnO and vanadium doped ZnO films deposited by pulsed laser deposition

Undoped ZnO films were deposited using pulsed laser deposition technique on Si and glass substrates in different O2 partial pressures (ranging from 10(-5) mbar to 3 mbar) and substrate temperatures. When the substrate temperature is 500 degrees C and O2 partial pressure (pp) approximately 3 mbar, randomly oriented ZnO hexagons were observed on glass substrate, whereas, dense ZnO hexagonal rod like structures (diameter ranging from 200-500 nm) were observed on Si substrate. The photoluminescence (PL) characterization of ZnO film grown on Si exhibited an intense defect free narrow excitonic emission in the UV region (Full width half maximum (FWHM) approximately 11.26 nm) as compared to broad emission (FWHM approximately 57.06 nm) from that grown on glass. The parent film emission was found to shift from UV to blue region on doping ZnO with Vanadium.     

Effect of Sn doping on structural, optical, electrical and wettability properties of oriented ZnO nanorod arrays

Herein we present a modified sol gel route for the one step fabrication of oriented ZnO nanorod arrays. The method is seed layer free, and nanorods directly attach to a substrate. We also present the effect of tin (Sn) content on the crystallinity, microstructural, optical and electrical properties of the ZnO nanorod arrays. Thermo gravimetric (TG) curves of gel precursors showed that most of the organic groups and other volatiles were removed at about 450 °C. X-ray diffraction patterns confirmed that the films were polycrystalline in nature with (002) preferred orientation. The texture coefficient, grain size, dislocation density and lattice parameters of the ZnO arrays were determined. The SEM micrographs revealed that the undoped and 1 at.%Sn doped films were composed of nanorods and the concentration of 2 at.%Sn doping hindered the rod like structure growth and modulated into granular nature. UV-visible transmission spectroscopy indicated that the transparency of the films increased with Sn content. On Sn doping, the films also exhibited a red shift and slight shrinkage of band gap. The electrical studies revealed that 1 at.% of Sn doping enhanced electrical conduction in ZnO films and beyond that the distortion caused in the lattice reduced the conductivity. The contact angle of the ZnO nanostructures varied between 91° and 115° depending upon the Sn content. Therefore, 1 at.%Sn doping into ZnO nanorods improves the crystallinity, electrical conductivity and water contact angle.     

Sputtering of ZnO:Al films from dual tube targets with tilted magnetrons

Aluminum doped zinc oxide (ZnO:Al) films were deposited by mid-frequency sputtering rotating tube targets at high discharge powers in a double cathode system. The magnetrons located inside the tube targets were tilted by ± 30°, leading to different racetrack orientations. Deposition rate and electrical properties of statically deposited films were investigated. Different properties of ZnO:Al films show lateral variations corresponding to the racetrack positions, which shift according to the tilt angles of double magnetrons. The highest average static deposition rate and the corresponding dynamic value were up to 360 nm/min and 111 nm m/min, respectively, for magnetrons tilted towards the center of the cathodes. The material properties of the ZnO:Al film prepared in dynamic mode were found to behave like the superpositions of properties of static films at different positions. Upon wet chemical etching in diluted hydrochloric acid (HCl), the surfaces of sputtered ZnO:Al films became rough, and three typical surface structures were observed and identified on statically deposited ZnO:Al films. The related plasma physics, growth and chemical etching mechanisms were discussed.     

不同电解液组成对TiO2纳米管形成的影响

电解液在阳极氧化中发挥着重要作用,对TiO2纳米管的形成与否,形成后管的成分、形貌都有着很大的影响.本实验采用了恒压阳极氧化方式,分别以HF(0.5wt%),(NH4)2SO4 HF(0.5wt%),(NH4)H2PO4 HF(0.5wt%),NaNO3 HF(0.5wt%)为电解液,在钛箔表面获得多孔TiO2膜.用FESEM观察了多孔膜的形貌并用EDX和XPS能谱对膜表面成分和构成进行测试分析.实验结果表明:在单一的HF酸电解液中加入(NH4)2SO4或(NH4)H2PO4后,阳极氧化生成的膜孔径明显减小,并且膜表面形态较差.加入NaNO3后,对膜的形貌影响不是很大.由EDX和XPS能谱分析得出,阴离子中的大部分非金属元素较难进入膜表面,而氮元素却很容易掺杂进入膜的表面形成N-Ti-O结构,从而影响膜的成分构成.这表明本实验利用简单电化学方法实现了N的掺杂.通过XRD测试得出,含不同阴离子的电解液对TiO2膜的晶型转变温度影响不大.     

热处理温度对溶胶-凝胶法制备ZnO薄膜晶体结构和发光特性的影响

采用溶胶-凝胶(Sol-Gel)旋涂法在Si(100)衬底上制备ZnO薄膜,利用X射线衍射(XRD)、光致发光谱(PL)、扫描电子显微镜(SEM)等手段分析制得的ZnO薄膜的晶体结构和发光特性。着重考察了热分解温度对ZnO薄膜晶体结构和发光特性的影响。结果表明,溶胶-凝胶旋涂法制备的ZnO薄膜样品厚度约为220nm,属六方纤锌矿结构,其c轴取向度与热分解温度有很大关系;ZnO薄膜在室温下均有较强的紫外带边发射峰,且紫外带边发射峰与样品c轴取向度没有直接关系,与缺陷有关的可见发射带很弱。     

沉积时间对脉冲激光沉积法制备ZnO薄膜性能的影响

采用脉冲激光沉积技术(PLD)在氧气气氛中以高纯Zn为(99.999%)靶材,在单晶硅和石英衬底表面成功生长了ZnO薄膜.通过X射线衍射仪、表明轮廓仪、荧光光谱仪、紫外可见分光光度计对合成薄膜材料的晶体结构、厚度、光学性质等进行了研究,分析了ZnO薄膜的沉积时间对其性能的影响.结果表明,采用PLD法在室温下可以制备出(002)结晶取向和透过率高于75%的ZnO薄膜,但室温下沉积的ZnO薄膜的发射性能较差,沉积时间的延长不能改善薄膜的发光性能.     

Enhancement of photoluminescence from ZnO film by single wall carbon nanotubes

Optical emissions from ZnO films were enhanced by a formation of hybrid structures with single wall carbon-nanotubes (SWCNTs). The SWCNTs were characterized by the presence of the associated fibers and islands together with many carbon nanotube structures and their average height was about < or = 40 nm from atomic force microscope and scanning electron microscope measurements. The intensities of photoluminescence on ZnO films with SWCNTs were increased up to about 30 and 60% in the region of 3.3 eV (near band edge) and 2.3 eV (deep-level) bands, respectively. It was considered that the enhancement of optical emissions from ZnO might be resulted from the effects of an excitation light scattering by SWCNTs and a surface plasmon resonance between bandgap of ZnO and SWCNTs. The surface plasmon resonance mode in the ultra-violet regions is smaller than the deep-level region relatively. This result showed that the commercial ZnO/carbon nanotubes have a feasibility of application to optoelectronic device.