直流电弧等离子体喷射法高速制备高质量纳米金刚石膜研究

利用直流电弧等离子体喷射法沉积装置在底径Ф65mm高5mm的Mo球面衬底上成功制备出纳米金刚石薄膜,文章研究了在稳定电弧状态下碳氢比对金刚石膜形貌的影响.通过扫描电子显微镜、原子力显微镜及Raman光谱对样品的晶粒尺寸及质量进行了表征. 研究结果表明: 在稳定电弧状态下,通过提高碳氢比可以在Mo球面衬底上的表面高速沉积出高质量的纳米金刚石薄膜, 晶粒尺寸大约为4～80nm,平均粒径27.4nm.     

Ag-MgO复合团簇薄膜微结构及其光学特性

用射频-磁控共溅射技术制备出Ag体积分数分别为5%,10%,15%和20%的Ag-MgO复合团簇薄膜.用X-射线衍射仪、原子力显微镜和紫外-可见分光光度计研究了复合团簇薄膜的微结构、表面形貌和光学性质.结果表明:随着Ag体积分数从5%增大到20%,薄膜中Ag的平均晶粒尺寸由8.2 nm增大到10.9 nm,薄膜的平均颗粒尺寸从37.9 nm增大到43.4 nm,方均根(rms)粗糙度先减小后略有增大,可见光范围内的平均透过率先下降后几乎保持不变.     

TiO_2–ZnO复合薄膜的制备及光致双亲性能

采用溶胶-凝胶法制备了TiO2薄膜和ZnO掺杂的TiOr-ZnO复合薄膜.通过X射线衍射和原予力显微镜表征了样品的晶相、晶粒尺寸和形貌.以水(H2O)作为极性溶液参照物,苯(C6H6)作为非极性溶液参照物,研究了煅烧温度、煅烧时间、薄膜层数对薄膜光致双亲性的影响.结果表明:煅烧温度和煅烧时间的不同能够导致薄膜的晶粒粒径、晶型及薄膜表面的粗糙度发生变化.从页影响薄膜的双亲性能.当煅烧温度为550℃,煅烧时间 为2h,薄膜层数为3层时.TiO2由锐钛矿相向金红石转变,薄膜的双亲性最传.TiO2-ZnO复合薄膜的晶粒粒径约为25.2nm,薄膜表面粗糙度约1.815 nm,此时,亲水角和亲油角分别为5°和4°.ZnO掺杂的TiO2复合薄膜的双亲性明显高于纯TiO2薄膜.     

纳米材料和纳米技术(Ⅲ)

<正> 纳米陶瓷(nanometer ceramics)纳米陶瓷是指晶粒尺寸在100 nm 以下的多晶陶瓷。广义地讲,纳米陶瓷材料包括:纳米陶瓷粉体,单相和复相的纳米陶瓷,纳米-微米复相陶瓷和纳米陶瓷薄膜。多晶陶瓷随着晶粒尺寸的逐渐减小,晶界密度不断升高,位于晶界处的原子数量也相应剧增。例     

纳米TiO2-CeO2复合薄膜的结构和光学性能

采用射频磁控溅射法在柔性基体聚对苯二甲酸乙二醇酯上制备了纳米TiO2-CeO2复合薄膜.采用x射线衍射仪、扫描电镜和紫外-可见光谱仪研究了薄膜的物相结构、表面形貌和镀膜样品的紫外-可见光透过率及光学能隙.结果表明:沉积态的薄膜为非晶态,经150℃退火处理12h后,转化为良好的晶态,薄膜中主要含有锐钛矿结构TiO2,未出现CeO2的特征峰.随退火时间的延长及CeO2含量的增加,复合薄膜表面的球形晶粒数量增多,尺寸增大,且复合薄膜的透光率增加,禁带宽度减小.特别是当CeO2质量分数为10%,退火处理时间为12h时,晶粒尺寸为120nm,薄膜表面结晶最好;吸收边波长和截止波长均发生红移,分别从常温下的431,338 nm增加至554,351 um,禁带宽度仅为(2.62±0.05)eV,提高了薄膜对太阳光或可见光的利用率.     

电子束辐照致VO2(A)薄膜光电特性改变

以能量为1.0MeV,剂量为1.2×1013～1.2×105/cm2电子束辐照VO2(A)薄膜.利用X射线衍射仪、扫描电镜、电阻温度测试仪和Fourier中红外光谱仪对电子辐照前后的薄膜进行测试,研究了辐照剂量对薄膜结构、光电特性的影响.结果表明:剂量为1.2×1013/cm2时,辐照主要是在薄膜中引入点缺陷:剂量为1.2×1015/cm2时.辐照在薄膜中产生明显的退火效应.辐照剂量增加会引起薄膜相变过程中电阻温度系数增加,使相变温度点发生变化,热滞回线宽度最大可增加89.1%,相变前后薄膜电阻值变化的数量级增大,晶粒尺寸经历了31.8nm→21.3nm→20.3nm→33.5nm的变化.半导体相薄膜的透过率受缺陷影响较大,金属相时主要受晶粒尺寸的影响.     

射频磁控溅射法制备PI基CeO2-TiO2复合薄膜

采用射频磁控溅射技术在柔性基体PI(聚酰亚胺)上制备了纳米CeO2-TiO2复合薄膜.借助X射线衍射(XRD)、原子力显微镜(AFM)和紫外-可见光谱仪分别研究了薄膜的物相结构、表面生长形貌和薄膜的紫外-可见光透过率及光学能隙,并用WS-2000型薄膜划痕仪测定薄膜与基体的界面结合强度.实验结果表明:沉积态的薄膜为非晶态,经200℃退火处理4h后,转化为良好的晶态,薄膜中主要含有锐钛矿相结构;溅射功率对薄膜的形貌,光学性能及界面结合力均有影响.尤其当溅射功率为120W时,薄膜的综合性能最优;平均晶粒尺寸110nm,表面粗糙度为160nm,吸光率达80%,光学能隙Eg仅为(2.65±0.05)eV,划痕法测量涂层与基体的附着力为60N.     

热处理对TiO_2薄膜微观力学性能的影响

采用喷涂法在5mm普通浮法玻璃上制备了纳米级锐钛矿型TiO2薄膜,并进行了不同温度的热处理。采用原子力显微镜、X射线衍射仪和纳米压痕仪分析了薄膜的形貌、结构和微观力学性能。讨论了热处理温度对纳米TiO2薄膜微观力学性能的影响。结果表明:随着热处理温度由20℃升高到500℃,薄膜中TiO2均变为锐钛矿型,平均晶粒尺寸略有增加,薄膜表面平整;随热处理温度从350℃升至500℃,平均粗糙度由12.516nm降低至11.433nm;热处理后纳米压痕硬度和弹性模量均有增加,分别由412.6MPa,14.9GPa增加到908.3MPa,28.4GPa;塑性指数逐渐增大,由0.028增大到0.032;摩擦因数由0.166降低到0.120。     

锑掺杂量对ATO薄膜结构及光、电性能的影响

以四氯化锡和三氯化锑为主要原料,采用溶胶-凝胶法制备了不同锑掺杂量的纳米锑掺杂二氧化锡（ATO）薄膜。分别利用XRD、FESEM、紫外可见分光光度计和四探针电阻仪对晶体结构、薄膜形貌、光透过率和薄膜方块电阻进行表征,考察锑掺杂量对ATO薄膜晶体结构、晶粒尺寸、光透过率和导电性能的影响。结果表明：所制备的ATO薄膜为（110）面择优取向的四方相锡石结构,晶粒尺寸小于26 nm,当锑掺杂量为10%（物质的量分数）时,ATO薄膜具有最小的方块电阻（60.1 Ω/□）,可见光透过率大于85%。     

TiO_2/SiO_2复合薄膜的晶型和晶粒尺寸研究

通过溶胶 -凝胶工艺在普通钠钙玻璃表面制备了均匀透明的TiO2 /SiO2 复合薄膜 .由紫外可见光谱发现 :在TiO2 薄膜中添加SiO2后 ,薄膜中TiO2 晶粒尺寸变小 ,TiO2 /SiO2 复合薄膜的吸收边缘波长发生了明显的“蓝移” .进一步用X射线衍射 (XRD)和透射电镜 (TEM )表征了TiO2 /SiO2 复合粉末和TiO2 粉末的晶型和晶粒尺寸 ,结果发现 :在TiO2 凝胶粉末中添加少量SiO2 (如摩尔分数为 5 % )后 ,TiO2 的晶粒生长受到明显抑制 ,晶粒尺寸明显变小 ,为 6～ 7nm ;当TiO2 凝胶粉末中添加的SiO2 量较高时 ,随热处理温度升高 ,TiO2 的晶型转变和晶粒生长受到更大抑制 ,晶型转变和晶粒生长更缓慢     

高定向ZnO纳米棒阵列膜的制备及其光学性能

采用阴极恒电位沉积方法,在Zn(NO3)2溶液中,用六亚甲基四胺作为形貌控制试剂,直接在氧化铟锡玻璃衬底上制备出透明致密的ZnO纳米棒阵列膜。通过X射线衍射、扫描电镜和能量色散谱表征了薄膜的形貌和结构,测量了ZnO纳米棒阵列膜的光学透射谱和光致发光谱。结果表明:所制备的具有c轴高度择优取向的ZnO纳米棒为高纯单晶纤锌矿结构,粒径约为200nm,膜的结晶度和表面平整度明显提高。ZnO薄膜在可见光区具有高透射率(80%)和陡峭的吸收边缘,室温光致发光谱显示,在380nm处存在一个尖锐的强紫外发射峰和在510nm处存在一宽带弱绿光发射峰。     

Nanocrystalline ZnO films deposited by spray pyrolysis: Effect of gas flow rate

ZnO is one of the multifunctional metal oxide semiconductors suitable for use in optoelectronic devices, as an alternative to tin oxide and indium oxide. Undoped ZnO films have been prepared using simple and cost-effective spray pyrolysis technique. In this work, we present detailed analysis of the structural, morphological and optical properties of ZnO films. X-ray diffraction spectra of the films have shown that the films are polycrystalline and hexagonal wurtzite in structure. The average grain size, estimated from the (002) peak using the Scherrer formula is around 40 ± 5 nm. The average optical transmittance of undoped ZnO thin films was about 80% in the visible. The AFM analysis reveals the surface topology having highly rough nature. The enhanced extinction coefficient varies with the flow rate. The EDX spectrum registers non-stoichiometric ZnO growth with O and Zn in 28.46 and 71.56 at. %. The features of the ZnO lead to the visible light transmission and efficient charge transport.     

溶胶-凝胶法制备ZAO薄膜及其结构与光学性能分析

以Zn（CH3COO）2·2H2O和Al（NO3）3·9H2O为主要原料，采用溶胶一凝胶法结合旋涂工艺以ITO玻璃为衬底制备获得掺Al型氧化锌透明导电薄膜（Zn2Al0.6O）。分别采用XRD和分光光度计测试分析了所制各薄膜的结构和透射光谱，并计算了薄膜的平均晶粒尺寸和光学带隙。结果表明，所制备薄膜为ZAO薄膜：薄膜平...     

Substrate temperature-dependent physical properties of nanocrystalline zirconium titanate thin films

Nanocrystalline zirconium titanate thin films were deposited by direct current magnetron reactive sputtering on to glass substrates at room temperature and at different substrate temperatures of 423, 473, 523, and 573 K under high vacuum conditions. The deposited films have been characterized to study the physical properties of the films as a function of substrate temperature. Though the film exhibited amorphous characteristics at room temperature the higher temperatures resulted in the evolution of crystallites in the films. The crystallinity increased with temperature from 423 K onwards and the film deposited at 523 K exhibited a high crystallite size of 22 nm. The SEM images of the films revealed the improvement in the crystallinity from 423 to 523 K with dense columnar structure normal to the substrate. Further higher treatment deteriorated the film properties. The films showed a good transmittance of above 80%. A high optical transmittance of 91% and a high packing density of 96% have been observed for the film deposited at 523 K. The thickness of the films remained consistent at ~230 nm (±6 nm). It is noticed that an increase in the substrate temperature enhanced the structural, optical, and electrical properties of the films up to 523 K.     

Structural and optical properties of ZnS thin films deposited by RF magnetron sputtering

Zinc sulfide [ZnS] thin films were deposited on glass substrates using radio frequency magnetron sputtering. The substrate temperature was varied in the range of 100°C to 400°C. The structural and optical properties of ZnS thin films were characterized with X-ray diffraction [XRD], field emission scanning electron microscopy [FESEM], energy dispersive analysis of X-rays and UV-visible transmission spectra. The XRD analyses indicate that ZnS films have zinc blende structures with (111) preferential orientation, whereas the diffraction patterns sharpen with the increase in substrate temperatures. The FESEM data also reveal that the films have nano-size grains with a grain size of approximately 69 nm. The films grown at 350°C exhibit a relatively high transmittance of 80% in the visible region, with an energy band gap of 3.79 eV. These results show that ZnS films are suitable for use as the buffer layer of the Cu(In, Ga)Se₂ solar cells.     

Direct synthesis and characterization of optically transparent conformal zinc oxide nanocrystalline thin films by rapid thermal plasma CVD

We report a rapid, self-catalyzed, solid precursor-based thermal plasma chemical vapor deposition process for depositing a conformal, nonporous, and optically transparent nanocrystalline ZnO thin film at 130 Torr (0.17 atm). Pure solid zinc is inductively heated and melted, followed by ionization by thermal induction argon/oxygen plasma to produce conformal, nonporous nanocrystalline ZnO films at a growth rate of up to 50 nm/min on amorphous and crystalline substrates including Si (100), fused quartz, glass, muscovite, c- and a-plane sapphire (Al2O3), gold, titanium, and polyimide. X-ray diffraction indicates the grains of as-deposited ZnO to be highly textured, with the fastest growth occurring along the c-axis. The individual grains are observed to be faceted by (103) planes which are the slowest growth planes. ZnO nanocrystalline films of nominal thicknesses of 200 nm are deposited at substrate temperatures of 330°C and 160°C on metal/ceramic substrates and polymer substrates, respectively. In addition, 20-nm- and 200-nm-thick films are also deposited on quartz substrates for optical characterization. At optical spectra above 375 nm, the measured optical transmittance of a 200-nm-thick ZnO film is greater than 80%, while that of a 20-nm-thick film is close to 100%. For a 200-nm-thick ZnO film with an average grain size of 100 nm, a four-point probe measurement shows electrical conductivity of up to 910 S/m. Annealing of 200-nm-thick ZnO films in 300 sccm pure argon at temperatures ranging from 750°C to 950°C (at homologous temperatures between 0.46 and 0.54) alters the textures and morphologies of the thin film. Based on scanning electron microscope images, higher annealing temperatures appear to restructure the ZnO nanocrystalline films to form nanorods of ZnO due to a combination of grain boundary diffusion and bulk diffusion.PACS: films and coatings, 81.15.-z; nanocrystalline materials, 81.07.Bc; II-VI semiconductors, 81.05.Dz.     

Hybrid Microwave Sintering of Infrared Transparent Nano‐Y3Al5O12 Synthesized by a Modified Combustion Technique

Infrared transparent ceramics found to have numerous civilian and defense applications. In the present work, Y₃Al₅O₁₂ nanoparticles were synthesized by an auto‐igniting modified single‐step combustion method. The structure and morphology of the as‐prepared powder revealed the phase purity and ultrafine nature of the powder having an average crystallite size of 16 nm and well‐defined lattice planes. Coupling of the resistive and microwave heating at precise proportion leads to a sintered density of the powder with 99.3% of the theoretical density at a temperature as low as 1470°C for a soaking duration of just 20 min. Marked reduction in grain size and the porosity was also observed for the hybrid sintered pellets. An average grain size of 167 nm was measured for the sintered pellets, which also showed a high transmittance of 80% in the UV–vis region and 82.5% in the mid‐IR region.     

Fabricating translucent polydimethylsiloxane (PDMS) super-hydrophobic surface greenly by facile water-dissolved fillers

In this study, a polydimethylsiloxane (PDMS) colloid was cast onto a template made of recycled polypropylene for structural duplication to fabricate translucent super-hydrophobic surfaces greenly without the use of any complicated method. The surface structure of the template was formed by hot embossing using salt grain fillers dissolved in water. The resulting contact angle (CA) values of fabricated PDMS surfaces were 153.4 ± 0.6°, 152.3 ± 1.8°, 152.2 ± 0.8°, and 152.0 ± 1.6° and the associated slide angle (SA) values were 5.8 ± 0.6°, 8.7 ± 1.5°, 8.6 ± 1.1°, and 16.3 ± 1.9° for filler grain size categories A, B, C, and D, respectively. The surfaces with grain sizes A, B, and C exhibited super-hydrophobic conditions, where CA > 150° and SA < 10°; on the other hand, the surface with grain size D exhibited an SA value greater than 10°. The measured percentages of light transmittance in the visible wavelength range of 400–800 nm were 75–80% for grain sizes B, C, and D and 85–90% for grain size A. Furthermore, a green laser light was diffused from a spot of 0.5–7.7 cm in diameter; related glare was also eliminated.     

Room temperature preparation of high performance AZO films by MF sputtering

Aluminum-doped zinc oxide (AZO) thin films have been deposited by MF magnetron sputtering from a ceramic oxide target without heating the substrates. This study has investigated effects of sputtering power on the structural, electrical and optical properties of the AZO films. The films delivered a hexagonal wurtzite structure with (002) preferential orientation and uniform surface morphology with 27–33 nm grain size. The results indicate that residual stress and grain size of the AZO films are dependent on sputtering power. The minimum resistivity of 7.56×10^?4 Ω cm combined with high transmittance of 83% were obtained at deposited power of 1600 W. The films delivered the advantages of a high deposition rate at low substrate temperature and should be suitable for the fabrication of low-cost transparent conductive oxide layer.     

多孔SiO2膜的制备和增透性能研究

采用溶胶-凝胶结合旋转涂膜法在玻璃基底上制备SiO2薄膜,研究了陈化时间和旋涂速度对SiO2膜增透性能的影响,利用热分析仪、X射线衍射仪、红外光谱仪、扫描电镜、分光光度计、椭偏仪等方法分别对干凝胶的热分解过程、晶体结构、微观形貌、透过率和折射率进行表征.结果表明:膜层透过率与制备条件有一定的规律,随着陈化时间的延长和旋涂速度的增加,增透峰中心波长发生了移动.在最佳工艺条件下,制备的SiO2薄膜具有较好的增透性能,在玻璃上镀SiO2增透膜后,峰值透过率(300～1000 nm)由90％提高到95％,其膜厚为315 nm,折射率为1.352,孔隙率为27％,进一步提高了可见光利用率.