TiO2纳米薄膜微观结构及光学性能研究

用sol-gel法制备了纳米TiO₂薄膜,用原子力显微镜(AFM)观察了薄膜的表面形貌,测量了薄膜的表面粗糙度(RMS)为2.832 nm;用红外光谱(IR)研究了TiO₂薄膜前驱体溶胶的组成; 探讨了TiO₂薄膜的焙烧温度、层数等制备条件对TiO2光催化活性的影响,结果发现在490℃,8层膜的TiO₂活性最高.     

溶胶-凝胶法制备SiO2-TiO2平板光波导工艺研究

采用溶胶-凝胶法制备了SiO₂-TiO₂平板光波导,计算了平板光波导通光条件,分析了硅/钛溶胶-凝胶材料的热性能,观测了平板光波导的结构形貌,并测试了其通光损耗。结果表明：经过200℃,30 min干燥处理的凝胶薄膜呈疏松多孔状态,对于非对称平板波导,存在芯层通光截止厚度,而且当SiO₂-TiO₂芯层厚度为0.5 μm时,SiO₂下包层厚度至少有6 μm才能防止1550 nm波长光泄露入单晶硅衬底中。制备的光波导对于1550 nm波长光传输损耗最小值为0.34 dB/cm。     

CdxHg1－xTe/SiO2固溶体微晶掺杂玻璃三阶非线性光学性质的

本文首次报道了对采用溶胶凝胶和原位生长工艺制备的Cd_xHg_1-xTe/SiO₂固溶体微品掺杂玻璃进行的三阶非线性光学性质实验研究及其结果。利用回返式简并四波混频技术,测得该固溶体掺杂玻璃的三阶非线性极化率的值为10^-12esu量级。此结果比纯SiO₂基体提高了2个数量级。表明该固溶体掺杂玻璃三阶非线性明显增强,在同样条件下,测得CS₂的三阶非线性极化率x⁽³⁾为(1.7±0.2)×10^-12esu,与国际上报道完全一致。     

Laser Resistance of Ta2O5/SiO2 and ZrO2/SiO2 Optical Coatings under 2μm Femtosecond Pulsed Irradiation

Ta₂O₅/SiO₂ and ZrO₂/SiO₂ high reflecting (HR) coatings are prepared by ion beam sputtering and electron beam evaporation, respectively. The laser-induced damage thresholds (LIDTs) of these samples are investigated with 2 μm femtosecond pulse lasers (80 fs, 1 kHz). It is found that the Ta₂O₅/SiO₂ HR coating has a higher capability of laser damage resistance than the ZrO₂/SiO₂ HR coating in the 2 μm femtosecond regime. The scanning electron microscope results show that the damage sites of the ZrO₂/SiO₂ HR coating have a relatively porous structure, the loose structure of coatings will provide more sites for water molecules, and the LIDTs of HR coatings will be reduced as a result of the strong water absorption at the wavelength of 2 μm.     

低成本溶胶-凝胶法制备SiO2/TiO2双层膜的减反射与自清洁性能

将玻璃基底依次在低成本的SiO₂溶胶和TiO₂溶胶中浸渍后,在500 oC下煅烧制备了同时具备减反射与自清洁性能的SiO₂/TiO₂双层膜．该膜的光学性能与结构特征分别通过紫外-可见分光光度计和场发射扫描电镜进行了表征．同时,源于超亲水性和光催化作用的自清洁性能也凸显出来．实验结果表明制备SiO₂/TiO₂双层膜对光的透射率最高可达到95%,同时具备自清洁性能．     

TiO2溶胶-凝胶光学膜制备工艺对其光学性质的影响

本文对TiO₂溶胶凝胶光学膜膜厚、折射率随不同温度作了在线测量,并讨论了在线温度对其光学性质的影响.考察了提拉速度对膜光学性质的影响。     

色散SiO2/TiO2薄膜组成的Fibonacci序列一维光子晶体在可见光波段的传输特性

用特征矩阵法研究了由正常色散SiO₂/TiO₂薄膜组成的Fibonacci序列一维光子晶体在可见光波段的传输特性,并与无色散时的传输特性做了对比。结果表明,随序列项数的增加,相应的前一序列的透射谱中透射率较低的凹带逐渐变成禁带,禁带数增加;初始介质是低折射率的SiO₂薄膜时比高折射率的TiO₂薄膜时各序列的透射谱中的禁带数多,各禁带的宽度和中心波长基本相同;在总厚度一定的条件下,随SiO₂薄膜的厚度增大（TiO₂薄膜的厚度减小）,禁带的宽度减小,禁带的中心波长基本不变;随入射角增大,禁带的中心波长向短波方向移动,禁带宽度变小。在其它相同条件下,无色散时的最宽禁带和最宽禁带的中心波长比有色散时的最宽禁带和最宽禁带的中心波长都有增加。     

多孔TiO2/Al/SiO2纳米复合结构的紫外光吸收特性研究

在SiO₂玻璃衬底上用脉冲激光沉积(PLD)技术，分别沉积Ti和Ti/Al膜，经电化学阳极氧化成功制备了多孔TiO₂/SiO₂和TiO₂/Al/SiO₂纳米复合结构. 其中TiO₂薄膜上的微孔阵列高度有序，分布均匀. 实验研究了Al过渡层对多孔TiO₂薄膜光吸收特性的影响. 结果表明：无Al过渡层的多孔TiO₂薄膜其紫外吸收峰在27     

紫外波段有机染料DMT掺杂SiO2薄膜的光谱特性

本文采用溶胶凝胶法合成了紫外波段有机染料DMT掺杂SiO₂薄膜和块体材料薄膜中掺杂浓度高达124×10^-2mol/L,块体材料浓度掺至15×10^-3mol/L由于SiO₂“笼”的束缚作用,在荧光光谱中未观察到荧光猝灭现象;由于SiO₂“笼”的极化作用,370nm的发射峰较其在环己烷中发生了34～44nm左右的红移;580～590nm的发射峰的量子效率比370nm的发射峰略高.     

改性剂对旋转法SiO2减反膜均匀性的影响

 分析了采用旋转涂膜法制备溶胶-凝胶SiO₂减反膜过程中条纹缺陷产生的机理,利用含氟醇类试剂对减反膜溶胶进行改性,使溶胶链段柔顺性及流动性得到改善。在光学显微镜下对改性前后的膜层进行了对比和分析,对膜层的表面形貌、表面粗糙度以及透射比等特性进行了表征。结果表明:溶胶改性之后的膜层未出现条纹缺陷,表面粗糙度均方根值从4.55 nm下降到小于1.00 nm,膜层表面质量有了较大提高;改性前后膜层的增透性能相当,在熔石英基片上制备的膜层峰值透射比为99.60%~99.89%,膜层激光损伤阈值为21.0~25.3 J/cm²。     

SiO_2/TiO_2复合薄膜的制备及其可见光透过率

采用溶胶凝胶法在载波片上制备了SiO2/TiO2复合薄膜。研究了TiO2含量、热处理温度、热处理时间、薄膜层数及溶胶陈化时间对其可见光透过率的影响。结果表明:复合薄膜的可见光透过率随TiO2含量的增加而降低;当TiO2含量为20%时,薄膜会出现"变白"现象;当热处理温度为80℃时,透过率最高;当TiO2含量为30%时,溶胶陈化时间为3天,镀膜两次,80℃/3h热处理所得到的薄膜透过率可达到基体的100%,耐磨性良好。初步检测显示,该薄膜具有一定的光催化活性。     

采用HfO2/SiO2溶胶-凝胶薄膜制备衍射光栅

采用溶胶-凝胶方法制备了具有光敏性的HfO2/SiO2溶胶-凝胶薄膜,并利用其光敏性制备了衍射光栅.采用XPS分析了薄膜的成份,证实了Hf元素的存在.并用椭偏仪测试了薄膜的折射率,结果证实了HfO2的加入确实提高了体系的折射率.利用其光敏性,采用X射线作曝光光源通过掩模进行曝光,利用曝光部分与未曝光部分的溶解度差,在薄膜上制备了高为0.8 μm、周期为1 μm的衍射光栅.     

A novel trilayer antireflection coating using dip-coating technique

We report a new structure for broadband antireflection coating by dip-coating technique, which has minimal cost and is compatible with large-scale manufacturing. The coatings are prepared by depositing SiO 2 sol-gel film on a glass substrate, subsequently depositing SiO 2 single-layer particle coating through electrostatic attraction, and depositing a final very thin SiO 2 sol-gel film to improve the mechanical strength of the whole coating structure. The refractive index of the structure changes gradually from the top to the substrate. The transmittance of a glass substrate has been experimentally found to be improved in the spectral range of 400 1 400 nm and in the incidence angle range from 0 to at least 45 . The mechanical strength is immensely improved because of the additional thin SiO 2 sol-gel layer. The surface texture can be applied to the substrates of different materials and shapes as an add-on coating.     

The effects of different heat treatment and atmospheres on the NMR signal and structure of TiO2-ZrO2-SiO2 sol-gel materials

The effects of different heat treatment schemes (i.e. successively or directly heated to particular temperatures) and atmospheres (air or nitrogen) on the solid-state NMR spectra obtained from (TiO(2))(0.15)(ZrO(2))(0.05)(SiO(2))(0.80) sol-gel materials are investigated. A combination of 1H, 13C, 17O and 29Si NMR is used. 29Si MAS NMR indicates that the extent of condensation of the silica-based network strongly depends on the maximum temperature the sample has experienced, but the condensation is largely independent of the details of the heat treatment scheme and atmosphere used. For sol-gel produced silicate-based materials the results show that the equilibrium structure at each temperature is reached rapidly compared to the time (2h) spent at that temperature. The 17O NMR results confirm that a nitrogen atmosphere does significantly reduce loss of 17O from the structure but care must be taken since there could be differential loss of 17O from the regions having different local structural characteristics.     

基于ZF6基底的可见光宽谱带高性能增透膜

以ZF6为基底,采用电子束蒸发物理气相沉积方法设计并制备了一种增透波长为0.4～0.8μm的宽谱带可见光区增透膜。薄膜材料仅含有TiO2和SiO2两种材料,分别作为高低折射率材料。利用Edinburgh光谱仪对双面镀制该膜系样品的透过率进行测量,测试结果表明：薄膜平均透过率达98.15%,实际样品的光学特性与设计结果基本相符,具有宽带的增透特性,减少了表面剩余反射。机械强度与环境测试表明：制备的薄膜具有良好的稳定性和牢固度,可以应用于可靠性要求较高的光学系统中。     

HfO2中ZrO2含量对266nm HfO2/SiO2多层膜反射率的影响

用两种不同纯度的HfO2材料与同一纯度的SiO2材料组合,沉积Λ／4规整膜系(HL)^11H形成266nm的紫外反射镜,发现反射率相差0．7％左右。用X光电子能谱法分析了高反膜中表层HfO2中的成分,发现ZrO2的含量相差一个数量级左右。为确定形成这种差别的原因,用辉光放电质谱法测定了这两种HfO2材料中锆(Zr)及其钛(Ti)、铁(Fe)的含量,发现Zr是其中的最主要的杂质,两种HfO2材料中Zr含量有一个数量级的差别。说明在266nm波段,HfO2中ZrO2的含量会对HfO2／SiO2高反膜的反射率造成影响。根据HfO2单层膜的光谱曲线,推算出了这两种材料的消光系数的差别,并用Tfcalc膜系设计软件进行理论和镀制结果的模拟,得到与实验测试一致的结果。     

Zn、Cu共掺杂TiO_2∶SiO_2薄膜材料的光学性能研究

用溶胶-凝胶法制得Zn、Cu共掺杂的TiO_2∶SiO_2凝胶,旋转法于玻璃基底涂膜,制得Zn、Cu共掺杂的TiO_2∶SiO_2薄膜,探讨了煅烧温度、煅烧时间及掺杂比例对其结构、形貌和性能的影响。采用XRD、FESEM、FTIR等测试技术对薄膜进行表征,并考察了其对甲基橙的光催化降解性能。XRD测试结果显示:薄膜样品的晶型为锐钛矿型,结晶良好。SEM谱图显示:薄膜微粒粒径小,分布均匀,表面平整、致密且无明显裂痕;紫外-可见光谱(UV-Vis)表明:Zn、Cu共掺杂的TiO_2∶SiO_2薄膜在紫外区和可见光区的吸光度明显增加,提高了对光的利用率;光催化性能测试表明:与纯相TiO_2对比,Zn、Cu共掺杂的TiO_2∶SiO_2薄膜对甲基橙的光催化降解率有较大提高,在600℃下焙烧2h的掺杂的量比为n(Ti)∶n(Si)∶n(Zn)∶n(Cu)=3∶2∶1.5∶4的薄膜样品光催化降解率最高。     

压敏漆基质SiO2溶胶制备及其性能研究

以正硅酸乙酯为前驱体，乙醇为溶剂，盐酸为催化剂，采用溶胶-凝胶法制备了用于压敏漆基质薄膜材料的SiO2溶胶。不同的成膜助剂对SiO2溶胶的涂膜性能影响较大，其中以异丙醇作为添加剂的溶胶涂膜性能最好。吸收光谱测试结果表明SiO2溶胶不吸收激发光，同时发射光谱研究结果表明SiO2溶胶发光波长为415nm左右，不影响压敏漆探针分子的发光。     

Self-Assembled TiO2/PSS Multilayer Films Studied by Slow Positron Spectroscopy

TiO2/PSS nano-structured multilayer films are fabricated by a layer-by-layer self-assembly method, and the deposition process and interface structure of films are studied in detail by slow positron spectroscopy. The results indicate that injection energy of positron at the interface between the substrate and the film shows a linear dependence on the number of bilayer, which suggests that the repeatability of the depositing process is good, and the thickness of films shows a linear increase with the number of bilayers adding. The calculated result of the film thickness shows that there is an overlay between the adjacent TiO2 nanoparticle layers.