The effect of SiO2 on TiO2 up-conversion photoluminescence film

In order to increase the photoelectric conversion efficiency of silicon solar cell, the up-conversion film has been tried to enhance the response of the solar cells to the infrared band. Yb³⁺, Er³⁺ co-doped SiO₂/TiO₂ composite films with different Ti/Si molar ratio were deposited on the glass substrate with sol–gel method and spin-coating technique. The effect of different molar ratio of Ti/Si on the film’s morphology and optical properties was investigated. The morphology, the absorption spectra and photoluminescence (PL) spectra of the film were tested and analyzed. After the film was annealed at 900 °C, the XRD diffraction pattern indicated that rare earths ions have evenly dispersed into the matrix lattice. The FT-IR showed that Si ions entered into the lattice of titanium dioxide, and the Ti–O–Si bonds came into being. When the film pumped with a laser of 980 nm, there were a dominant red emission and several weak green peaks. In addition, with the increase of the mole ratio of Si/Ti, the intensity of the film’s up-conversion luminescence increases at first and then decreases. When the molar ratio of Si/Ti is 1/8, the sample had the highest intensity of up-conversion luminescence.     

TiO2/SnO2复合薄膜光诱导超亲水性机理的XPS研究

利用X射线光电子能谱仪对用溶胶-凝胶法制备的TiO2/SnO2复合薄膜的表面化学状态进行分析,结果表明:热处理及紫外光照前后,薄膜表面的化学状态均发生了变化,薄膜表面的碳氧或过氧化物基团增加,这些基团具有较强的活性,通过氢键和水中的极性基团作用,产生超亲水性.此外,掺杂SnO2提高了TiO2/SnO2复合薄膜的表面能,改变了薄膜表面的化学结构,使TiO2薄膜获得了较好的亲水性能和催化活性.     

WO3+掺杂对纳米TiO2薄膜可见光致亲水性的影响

用溶胶-凝胶法和浸渍-提拉工艺在载波片上制备了均匀、透明的WO^3＋掺杂的纳米TiO2薄膜.用XRD、紫外-可见分光光度计分析了样品的晶相和光吸收性能,研究了WO^3＋的掺杂、掺杂量及热处理温度对薄膜可见光致亲水性的影响,并考察了薄膜在停止光照后,其亲水性能的变化.结果表明,与纯TiO2薄膜相比,掺WO^3＋的TiO2薄膜对可见光的吸收有所增强,并有一定的红移现象,且在可见光照射下,亲水性能都有提高,WO^3＋的最佳掺杂量为3%（物质的量比）;薄膜的最佳煅烧温度为773K;停止光照后,掺WO3＋的TiO2薄膜亲水性能持续的更久.     

Enhanced photocurrent of nitrogen-doped TiO2 film for dye-sensitized solar cells

Nitrogen (n)-doped titanium dioxide (TiO₂) was prepared with varying doping extent by a general sol–gel process with a pure TiO₂ film as the control sample. The n-doped-2 electrode showed the maximum conversion efficiency with an open-circuit voltage (V_oc) of 0.726 V, a photocurrent (J_sc) of 10.52 mA cm^?2, a fill factor of 63.6%, and an efficiency of 4.86%, compared to 0.751 V, 7.4 mA cm^?2, 67.1%, and 3.73%, respectively, for the undoped (u-doped) TiO₂ electrode. The approximate 23% enhancement in the conversion efficiency of the n-doped-2 TiO₂ electrode-based dye-sensitized solar cells (DSSCs) was mostly ascribed to the increase of light absorption in the near-vis absorbance and partially to the morphological characteristics of the n-doped TiO₂ film. Additionally, the doping type of nitrogen in the TiO₂ lattice was closely studied using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The relation between the doping type and the electron behavior in the DSSCs was also examined.     

TiO2薄膜超亲水特性的研究

采用溶胶-凝胶法制备TiO2薄膜，研究了薄膜厚度、孔隙率、热处理温度、掺杂等因素对滞膜亲水性的影响，结果表明：当TiO2薄膜的厚度小于87.2nm时，随着膜厚的增加，接触角降低。当膜厚大于87.2nm时，接触角基本不变；孔隙率的增加，掺杂SnO2均有利于超亲水性的改善，热处理温度为450～662℃时薄膜亲水性最好。     

The modification effect of gamma-ray grafting of TiO2 on PET film

Commercial nanofiltration polyethylene terephthalate (PET) thin-film composite membranes were treated by low-pressure gamma-ray plasma, and the effects of the plasma treatment were investigated in terms of the membrane hydrophilicity, thickness and deposition rate. Experimental results indicated that the membrane surface hydrophilicity was increased by the plasma treatment and changes in the hydrophilicity, as well as membrane performance including yield strength varied with the original membrane characteristics (e.g., roughness and hydrophilicity).     

The effect of SiO2 addition in super-hydrophilic property of TiO2 photocatalyst

The relation between the effect and the amount of SiO₂ addition on photo-generated hydrophilicity of TiO₂ thin film, was investigated by measuring the X-ray diffraction, the microstructure, the specific surface area and the TG-DTA. It was found that the optimum range existed in the amount of SiO₂ addition to TiO₂, 10–30 mol % SiO₂ addition was most effective for contact angle of water. The SiO₂ addition less than 30 mol % has a suppressive effect on the transformation of anatase to rutile and on the crystal growth of anatase in calcination, and it has large surface area. With the consequence that the photocatalytic activity of TiO₂ and the capability of holding absorbed water which increases during UV irradiation improved.     

溶胶—凝胶法制备TiO2—SiO2复合薄膜的研究

采用溶胶－凝胶方法在单晶Ｓｉ基片上制备了ＴｉＯ２－ＳｉＯ２复合薄膜，研究了溶剂、ｐＨ值对先体溶液成胶时间的作用，溶液的浓度、甩胶时的旋转速度、涂覆层数以及热处理温度对薄膜厚度、光学性能的影响。薄膜的折射率随温度增大，其主要贡献来自于薄膜中结构的变化。并测量了薄膜的Ｉ－Ｖ、Ｃ－ｆ特性，由于薄膜中的热击穿效应而使得ＴｉＯ２含量较高的薄膜２的Ｉ－Ｖ呈非线性变化。     

TiO2溶胶对SMA-PVDF共混合金膜的亲水化改性研究

考察了TiO2溶胶对SMA（苯乙烯-马来酸酐交替共聚物）-PVDF（聚偏氟乙烯）共混合金膜的亲水性能的影响。TiO2溶胶由钛酸四异丙酯可控水解制得。SMA-PVDF共混合金膜由浸没沉淀相转化法制得。通过液相沉积法将TiO2溶胶涂覆于SMA-PVDF共混合金膜表面，即得到TiO2／聚合物复合膜。结果表明，相对于聚合物原膜，TiO2／聚合物纳米复合膜的亲水性能提高。纯水接触角由97°下降到62°左右。     

SiO2-TiO2亲水薄膜的制备及热处理对其亲水性能的影响

为了制备在自然光下具有良好的亲水性能的SiO2-TiO2薄膜,实验用溶胶-凝胶法以正硅酸乙酯(TEOS)和钛酸丁酯(TBOT)为前驱体水解制备SiO2-TiO2溶胶;采用浸渍提拉法在普通载玻片上涂膜;然后分别运用微波炉和马弗炉两种不同的烧结方式进行热处理制得产品.将所得产品分别进行接触角、紫外-可见分光光度计、IR、XRD和SEM测试.结果表明:马弗炉烧结得到的SiO2-TiO2薄膜亲水性要好于微波炉烧结,并且在VTEOS:VTBOT=0.75时,接触角最小,可达到4.3°,在自然光照15 s后,水滴可以在薄膜表面完全铺展开,达到0°,满足防污自清洁的要求;马弗炉和微波炉烧结的产品的红外谱图说明有Ti-O-Si键的生成,证明SiO2和TiO2之间生成了复合氧化物,但相比于马弗炉,微波炉所制产品的亲水基团在烧结过程中可能遭到破环.     

Enhanced photocatalytic property of nanoporous TiO2/SiO2 micro-particles prepared by aerosol assisted co-assembly of nanoparticles

Nanoporous TiO₂/SiO₂ composite micro-particles were prepared by an aerosol assisted co-assembly (AACA) and their characteristics were investigated for photocatalytic application. The average diameter of resulting co-assembled TiO₂/SiO₂ particles was ranged 4–10 μm, and increased as the precursor concentration increased. The TiO₂/SiO₂ particles were spherical in shape and pores ranged 1–100 nm in diameter. Photocatalytic activity of the as-prepared nanoporous TiO₂/SiO₂ particles was evaluated by measuring the photodegradation of methylene blue (MB) and NO_x. Furthermore, the photocatalytic activity of nanoporous TiO₂/SiO₂ particles was compared with those of commercial TiO₂ nanoparticles and nanoporous TiO₂ particles. The nanoporous TiO₂/SiO₂ particles exhibited the highest photodegradation of MB and NO_x among three samples, which was 80% after 3 h and 55% at 10 min, respectively.     

TiO2薄膜光诱导超亲水性作用机理的研究

通过对固体表面亲水性作用原理的分析,提出"纳米TiO2薄膜本身就具有良好的亲水特性,与其是否具有光催化特性不直接相关"的观点,并建立了TiO2薄膜光诱导超亲水性的作用模型,分析了影响光诱导超亲水性的主要因素.     

Enhanced giant magnetoimpedance effect in FINEMET/TiO2 composite ribbons

In order to study the influence of semiconductors on the magnetic properties and giant magnetoimpedance effect of FINEMET ribbon, titanium dioxide coating layer with different thickness was sputtered onto the free surface of the FINEMET ribbon by RF magnetron sputtering to prepare the FINEMET/TiO₂ composite ribbons. The morphology, magnetic properties, and giant magnetoimpedance of the FINEMET/TiO₂ composite ribbons were analyzed. The results show that the GMI ratio of composite ribbons first increases and then decreases with the increase of TiO₂ layer thickness (0?~?150 nm). When the thickness of TiO₂ thin film is 100 nm, the GMI ratio reaches the maximum 57.3%, which indicates that a certain thickness of TiO₂ thin film can significantly improve the GMI effect. The result can be explained by the combined result of electromagnetic interaction and stress between TiO₂ thin film and the FINEMET ribbon.

     

PVA对SiO2减反膜表面结构的影响

以正硅酸乙酯(TEOS)为有机硅源,乙醇为溶剂,NH3.H2O为催化剂,采用溶胶-凝胶技术,加入PVA(聚乙烯醇)添加剂,在玻璃上用旋涂法制备减反膜,并对其进行热处理;分别采用椭偏仪和扫描电镜对所制备减反膜的结构、物性进行研究,研究PVA添加剂对减反膜结构、折射率的影响。结果表明:适量的PVA添加剂可以控制SiO2太阳电池减反膜的开裂。     

Surface electromigration of Au-Ag binary film on SiO2

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

SiO2气凝胶柔性保温隔热薄膜

由SiO2气凝胶、聚酰亚胺和镀铝层(SiO2／PI／Al)组成的柔性多层薄膜具有很好的保温隔热特性和广泛的应用前景。采用溶胶-凝胶方法制备的SiO2气凝胶具有很高的气孔率和很低的体积密度，尝试了在溶胶-凝胶过程申先酸性后碱性的二步法催化．使孔洞率提高到97％，体积密度降低为50kg／m^3，成为优秀的保温隔热的主体材料。选择柔性耐温隔热的聚酰亚胺作为骨架材料，并用真空蒸发镀制上金属铝膜与多孔SiO2气凝胶复合成保温隔热薄膜。当薄膜叠加到10层时其保温隔热效果可提高5倍。     

SiO2薄膜制备的现行方法综述

在导电基体上制作薄膜传感器的过程中,需要在基体与薄膜电极之间沉积一层绝缘膜.二氧化硅薄膜具有良好的绝缘性能,并且稳定性好,膜层牢同,长期使用温度可达1000℃以上,应用十分广泛.通常制备SiO2薄膜的现行方法主要有磁控溅射、离子束溅射、化学气相沉积、热氧化法、凝胶-溶胶法等.本文系统阐述了各种方法的基本原理、特点及适用场合,并对这些方法做了比较.