基于磁控溅射与退火工艺制备的纳米结构VO2薄膜特性的研究

氧化钒（VOx）根据不同价态表现出不同的电学特性,其电学和光学特性还与薄膜的结构有关。通过不同的沉积方法,可以得到不同态的氧化钒。目前制备氧化钒薄膜的方法有真空蒸镀、溅射、气相沉积和溶胶-凝胶法等。适当改变制备条件可以制得不同结构的氧化钒薄膜,这种结构对薄膜的性能会产生明显的影响。     

四苯基卟啉锌-单壁碳纳米管复合薄膜的制备与光电特性研究

使用喷涂法制备了四苯基卟啉锌(ZnTPP)薄膜及ZnTPP-单壁碳纳米管复合薄膜。采用金相显微镜、扫描电子显微镜、台阶仪、四探针测试仪、紫外-可见光分光光度计、傅里叶红外光谱仪对薄膜的形貌、电学及光学性能等进行了系统的测量,研究了ZnTPP薄膜及ZnTPP-碳纳米管复合薄膜的太赫兹响应特性。结果表明,ZnTPP的太赫兹指纹谱峰为44,57,77,88,95和102 cm-1,与文献[3]报道的棕树叶中叶绿素的指纹谱峰基本一致。重要的是,通过与碳纳米管相复合的方法,不仅使ZnTPP有机薄膜的均匀性及致密性得到了改善,还使后者的导电性及在紫外到太赫兹波段的光吸收性能获得明显增强。此外,还发现了复合薄膜在47及66 cm-1处出现新的太赫兹吸收峰,证明了碳纳米管和ZnTPP之间存在的相互作用。这种作用使复合薄膜的综合性能得到提高。结果表明,通过加入碳纳米管,能够对ZnTPP的薄膜质量以及电学和光学性能等进行有效的改善,使之具有综合优良的物理性能、具备光电器件的应用前景。研究成果对促进有机物的太赫兹光谱研究以及寻找新型太赫兹有机敏感材料等具有重要意义。     

水溶性多壁碳纳米管/铜酞菁染料

采用化学氧化法制备了可溶性多壁碳纳米管,借助超声作用把可溶性多壁碳纳米管分散在水中形成水溶胶,采用自组装技术制备了可溶性多壁碳纳米管/铜酞菁染料的复合薄膜,采用原子力显微镜、红外光谱、吸收光谱和荧光光谱对可溶性多壁碳纳米管及其水溶胶、自组装复合薄膜进行了表征.实验结果显示多壁纳米碳管水溶胶具有较好的组装成膜性能,吸收光谱结果表明染料分子在膜内形成了J聚集体,荧光光谱结果表明复合薄膜的荧光来自于铜酞菁染料,引入多壁碳纳米管对染料分子的荧光发射特性有一定影响.     

溶胶凝胶制备氧化钒薄膜的生长机理及光电特性

采用溶胶凝胶法, 在不同的退火温度下制备了不同的氧化钒薄膜. 利用扫描电子显微镜、X射线衍射仪、高阻仪、紫外-可见分光光度计和傅里叶红外光谱仪等, 对薄膜的形貌、晶态、电学和光学特性进行了分析. 结果表明, 溶胶凝胶法获取V₂O₅薄膜的最佳退火温度为430 ℃, 低于此温度不利于使有机溶剂充分分解, 高于此温度则V–O键发生裂解、形成更多的低价态氧化钒. 本文制备的氧化钒薄膜具有较高的电阻温度系数和光吸收率, 适合应用在非制冷红外探测器中. 本文揭示了溶胶凝胶法制备氧化钒薄膜的生长机理. 关键词： 氧化钒薄膜 溶胶凝胶 光电特性 生长机理     

直流磁控溅射制备氧化钒薄膜

讨论了在低温下以高纯金属钒作靶材,用直流磁控溅射的方法制备出了氧化钒薄膜。通过设计正交试验,分析了氩气和氧气的流量比,溅射功率,工作压强,基底温度对氧化钒薄膜沉积速率和电阻温度系数TCR的影响,采用RTP-500型快速热处理机对氧化钒薄膜样品进行了退火热处理,实验结果表明:当Ar与O2的比例为100:4,溅射功率为120W,工作压强为2Pa时,所获得薄膜TCR较大,都在-2%/K附近,最高的可达-3.6%/K。     

不同厚度阴极修饰材料LiF对聚对苯乙炔MOPPV-SWNT-PbSe量子点复合材料太阳电池性能的影响

基于碳纳米管的良好导电性、激子传输性能和量子点聚合物复合材料高的光电转换性能,采用原位缩合法制备了聚合物聚(2-甲氧基-5-辛氧基)-对苯乙炔-功能化碳纳米管-硒化铅量子点复合材料.通过对复合材料的X射线衍射、透射电子显微镜和紫外可见吸收光谱研究,发现聚合物聚(2-甲氧基-5-辛氧基)-对苯乙炔,功能化碳纳米管与硒化铅量子点可以有效地复合,且功能化碳纳米管与聚合物聚(2-甲氧基-5-辛氧基)-对苯乙炔形成网状结构;硒化铅量子点尺寸为5.75nm,其可均匀地分散在聚合物聚(2-甲氧基-5-辛氧基)-对苯乙炔-功能化碳纳米管基体中形成包覆或镶嵌结构,并发生了光诱导电荷转移.通过对复合材料的光电性能研究发现,插入不同厚度阴极修饰材料LiF后其光电性能提高,且当LiF为3nm时,开路电压为0.558 V,短路电流为2.338 mA,填充因子为37.6%,转换效率为0.466%,与不插入修饰材料时相比复合材料光电性能提高了30%.     

花状掺杂W-VO_2/ZnO热致变色纳米复合薄膜研究

为解决掺杂引起的二氧化钒薄膜的红外调制幅度下降以及二氧化钒复合薄膜相变温度需要进一步降低等问题,采用纳米结构、掺杂改性和复合结构等多种机理协同作用的方案,利用共溅射氧化法,先在石英玻璃上制备高(002)取向的Zn O薄膜,再在Zn O层上室温共溅射沉积钒钨金属薄膜,最后经热氧化处理获得双层钨掺杂W-VO2/Zn O纳米复合薄膜.利用X射线衍射、X射线光电子能谱、扫描电镜和变温光谱分析等对薄膜的结构、组分、形貌和光学特性进行了分析.结果显示,W-VO2/Zn O纳米复合薄膜呈花状结构,取向性提高,在保持掺杂薄膜相变温度(约39?C)和热滞回线宽度(约6?C)较低的情况下,其相变前后的红外透过率差量增加近2倍,热致变色性能得到协同增强.     

VO_2/AZO复合薄膜的制备及其光电特性研究

采用直流磁控溅射和后退火氧化的方法在掺铝氧化锌(AZO)导电玻璃上制备了二氧化钒(VO2)薄膜,研究了不同的退火温度、退火时间对VO2/AZO复合薄膜制备的影响,并对复合薄膜的结构、组分、光电特性进行了测试与分析.结果表明,导电玻璃上的AZO没有改变VO2的取向生长,但明显改变了VO2薄膜的表面形貌特征.与用相同工艺和条件在普通玻璃基底上制备的VO2薄膜相比,VO2/AZO复合薄膜的相变温度降低约25?C,热滞回线宽度收窄至6?C,相变前后可见光透过率均在50%以上,1500 nm处红外透过率约为55%和21%,电阻率变化达3个数量级.该复合薄膜表面平滑致密,制备工艺简单,性能稳定,可应用于新型光电器件.     

纳米二氧化钒薄膜的电学与光学相变特性

采用双离子束溅射氧化钒薄膜附加热处理的方式制备了纳米二氧化钒薄膜。在热驱动方式下,分别利用四探针测试技术和傅里叶变换红外光谱技术对纳米二氧化钒薄膜的电学与光学半导体-金属相变特性进行了测试与分析。实验结果表明,电学相变特性与光学相变特性之间存在明显的偏差,电学相变温度为63 ℃,高于光学相变温度,60 ℃;电学相变持续的温度宽度较光学相变持续温度宽度宽;在红外光波段,随着波长的增加,纳米二氧化钒薄膜的光学相变温度逐渐增大,由半导体相向金属相转变的初始温度逐渐升高,相变持续的温度宽度变窄。在红外光波段,纳米二氧化钒薄膜的光学相变特性可以通过光波波长进行调控,电学相变特性更适合表征纳米VO₂薄膜的半导体-金属相变特性。     

氧化法结合快速热处理制备VOx薄膜及其性质研究

采用磁控溅射法在单晶Si〈100〉基底上沉积金属钒(V)薄膜,在高纯氧环境下快速热处理制备具有相变特性的氧化钒(VOx)薄膜.利用X射线衍射仪、X射线光电子能谱和扫描电子显微镜对薄膜结晶结构、薄膜中V的价态与组分及表面微观形貌进行分析,应用四探针测试方法和太赫兹时域频谱技术对样品的电学和光学特性进行测试.结果表明:在一定范围的快速热处理保温温度和保温时间下,都可以制备出具有热致相变特性的氧化钒薄膜,相变前后薄膜的方块电阻变化超过两个数量级,薄膜成分主要由V2O5和VO2混合组成,薄膜中V整体价态不因热处理条件改变而不同.在快速热处理条件范围内,500℃ 25 s左右条件下(中温区)制备出的氧化钒薄膜相变特性最佳,并且对THz波有一定的调制作用.     

脉冲溅射V2O5薄膜结构和性能研究

V2O5薄膜具有很好的离子注入/退出可逆性,是最有潜力的锂离子储存层的候选材料之一,它的电学特性与制备方法、化学计量比、结构和取向等有直接关系,仔细控制工艺参量是制备出在锂电池上应用的V2O5薄膜关键。研究中采用脉冲磁控反应溅射方法,通过精确地控制氧分压、基底温度等关键工艺参量,在石英玻璃和硅片上制备V2O5薄膜。利用X射线衍射和X射线光电子谱,分析了薄膜的成分、相结构、结晶和价态情况,用原子力显微镜表征了薄膜的微观结构,用分光光度计测量从200—2500nm波段V2O5薄膜纯度高、相结构单一、结晶度好。高低温电阻变化2个量级,薄膜的光学能隙为2.46eV。     

多组分复合薄膜的光学、电学、机械性能及其应用

复合薄膜因其可具有比单组份薄膜更加优异的性能而得到广泛的应用。通过以膜层的防护、催化、电学、光学以及力学性能等复合思想为切入点，阐述了通过膜层的复合掺杂旨在增强合金的抗腐蚀性，提高润滑摩擦性能，改善膜层的导电性能以及进行光学薄膜折射率和光谱吸收的调控，增强膜层的硬度及拉伸强度等机械性能的方法。对国内外的相关前沿成果进行简要介绍，并对复合薄膜的未来发展进行展望，为相关领域的研究提供参考。     

纳米VO2/ZnO复合薄膜的热致变色特性研究

为提高VO₂薄膜的热致变色性能,采用纳米结构和复合结构二者相结合的方法,通过磁控溅射技术先在玻璃衬底上制备高(002)取向ZnO薄膜,再在ZnO层上室温沉积钒金属薄膜,最后经热氧化处理获得纳米结构VO₂/ZnO复合薄膜.利用变温拉曼光谱观察分析了VO₂/ZnO薄膜相变前后的晶格畸变和键态的演变过程,讨论了薄膜的结构与热致红外开关特性和相变温度的内在关系.结果显示,与相同条件获得的同厚度的单层VO₂薄膜相比,纳米VO关键词： ZnO 2')" href="#">VO₂ 纳米复合薄膜 热致变色 拉曼光谱     

X- and gamma-ray irradiation effects on vanadium pentoxide thin films

Thickness and composition of thin films can be measured with X- and gamma-rays. In this work, thickness and composition of vanadium pentoxide thin films are investigated by energy dispersive and wavelength dispersive X-ray fluorescence systems. Also, the surface analysis of vanadium pentoxide thin films irradiated with Rhodium Kα X-rays and 59.54?keV gamma-rays emitted from 100?mCi and 5?Ci Americium-241 radioactive sources is performed by scanning electron microscope. It is observed that X- and gamma-rays are destructive for vanadium pentoxide thin films. Also, the composition of vanadium pentoxide thin films changes by irradiation with X- and gamma-rays.     

Influence of Concentration of Vanadium in Zinc Oxide on Structural and Optical Properties with Lower Concentration

ZnO films doped with different vanadium concentrations are deposited onto glass substrates by dc reactive magnetron sputtering using a zinc target doped with vanadium. The vanadium concentrations are examined by energy dispersive spectroscopy （EDS） and the charge state of vanadium in ZnO thin films is characterized by x-ray photoelectron spectroscopy. The results of x-ray diffraction （XRD） show that all the films have a wurtzite structure and grow mainly in the c-axis orientation. The grain size and residual stress in the deposited films are estimated by fitting the XRD results. The optical properties of the films are studied by measuring the transmittance. The optical constants （refractive index and extinction coefficient） and the film thickness are obtained by fitting the transmittance. All the results are discussed in relation with the doping of the vanadium.     

Electrical,optical and structural properties of pure and gold-coated VO2 thin films on quartz substrate

In the present study, vanadium dioxide films were grown on quartz glass substrate by reactive KrF laser ablation technique using a vanadium dioxide target. The gold films of various thicknesses were then deposited on the VO₂ film by sputtering technique. Films were characterized by X-ray diffraction to determine crystallography, by four-point probe to determine the electrical property and by double-beam spectrophotometry to determine optical reflection and transmission behaviour in the 200–2500 nm spectral region. The resistance per square of VO₂ thin film decreases by two orders of magnitude across the metal insulator transition (MIT). The optical transmittance and reflectance exhibits, strong temperature dependence in the infrared region without a significant change in the visible region for VO₂ thin films. The presence of gold layer on VO₂ films significantly reduces the resistance per square, the critical temperature and percentage transmittance of the materials.     

Cu-In-O composite thin films deposited by reactive DC magnetron sputtering

Cu-In-O composite thin films were deposited by reactive DC magnetron sputtering at room temperature. The samples were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV/vis spectrophotometer, four-probe measurement and Seebeck effect measurement, etc. The samples contain Cu, In and O. The ratios of Cu to In and O to In increase with increase in O₂ flow rates. The ratio of Cu to In is over 1 and this suggests that Cu is in excess. The obtained Cu-In-O thin films are very possibly made of rhombohedral In₂O₃ and monoclinic CuO. Transmittance of the films decreases with increase in O₂ flow rate. The decrease in transmittance results from increase in Cu content in the films. The optical band gap of all the samples is estimated to be 4.1-4.4 eV, which is larger than those of In₂O₃ and CuO. The sheet resistance of the films decreases with increase in O₂ flow rate. Conductivity of the films is a little low, due to the addition of Cu and the poor crystalline quality of the film. The conduction behavior of the films is similar to that of In₂O₃ and the conduction mechanism of Cu-In-O thin films is through O vacancy.     

Tribological Properties of Surface-Modified Graphene Filled Carbon Fabric/Polyimide Composites

To improve the wear resistance of carbon fabric reinforced polyimide (CF/PI) composite, surface-modified graphene (MG) was synthesized and employed as a filler. The flexural strength, Rockwell hardness and thermal properties of the composites were tested. The composites were also evaluated for their tribological properties in a ring-on-block contact mode under dry sliding conditions. The results showed that the wear rate of MG reinforced CF/PI composites was reduced when compared to unfilled CF/PI composite. It was found that the 1?wt% MG filled CF/PI composites exhibited the optimal tribological properties. The worn surface, wear debris and transfer films were analyzed by scanning electron microscopy (SEM) and optical microscopy (OM) with the results helping to characterize the wear mechanism.