与Si集成的溶胶—凝胶法制备的TiO2—SiO2复合薄膜的应力分析

采用激光束反射偏转法测量了用溶胶－凝胶法在Ｓｉ（１１）基片上制备的ＴｉＯ２－ＳｉＯ２复合薄膜的曲率半径。由此计算出薄膜的热应力，应力和本征应力。研究了工艺过程与薄膜应力的关系，其应力随热处理温度的增加而由张应力转变为压应力；当热处理温度较低时，随膜厚的增加，其应力增大，而最终导致膜的开裂，薄膜的最大不开裂厚度随热处理温度和ＴｉＯ２含量的增加而增加。     

SiO2—Al2O3复合氧化物薄膜的溶胶—凝胶法制备研究

以ＴＥＯＳ和水合硝酸铝为原料用溶胶－凝胶法制备复合溶胶，对制备条件进行了研究，并用上述溶胶在不锈钢基体上制备了ＳｉＯ２－Ａｌ２Ｏ３复合氧化物薄膜。结果表明，该薄膜在适当组成时具有良好的完整性。当硝酸铝含量过高时溶胶和凝胶的均匀性受到影响。     

Au掺杂TiO2／SiO2薄膜的光学非线性特性研究

采用溶胶－凝胶方法制备了Ａｕ掺杂的ＴｉＯ２／ＳｉＯ２复合薄膜（厚度约为１．０μｍ）。Ｘ－ｒａｙ衍射分析表明，Ａｕ的颗粒镶嵌在ＴｉＯ２／ＳｉＯ２复合薄膜的玻璃网络中。谢乐公式计算给出Ａｕ的颗粒大小约为１０ｎｍ。采用Ｚ－Ｓｃａｎ测量技术得此薄膜的光学非线性折射率为１．０９×１０－７ｅｓｕ。     

纳米SiO2基质中Eu3+的发光特性

采用溶胶凝胶法(sol-gel)制备了Eu3+掺杂SiO2基质发光材料,分别用荧光(PL)光谱、原子力显微镜(AFM)、扫描电镜(SEM)等分析手段对样品进行了表征,研究了退火温度以及掺杂浓度对发射光谱的影响,并对其发光机制进行了分析.薄膜样品在258 nm光激发下,在620 nm,667 nm处出现了比较少见的双峰红光发射,而620 nm处的光发射最强,说明Eu3+离子处在对称性较低的配位环境中.退火处理温度对样品的发射光谱影响很大,经900 ℃退火处理的样品发射强度最强.随着掺杂浓度的变化,改变了Eu3+ -O2-间的距离,在相同紫外光激发下O2-外层的电子迁移到Eu3+ 4f轨道上的能量变化,使得谱线位置出现了移动.     

空芯波导用SiO2—TiO2—GeO2涂层的红外反射光谱分析

指出对于SiO2-TiO2凝胶玻璃涂层，即使TiO2含量高达80%，其对CO2激光波长(10.60μm）的IR反射率值仍很低。而对于SiO2-TiO2-GeO2涂层，当GeO2的含量从20%增加到30%时，其反射率峰逐步移向CO2激光波长，且在10.6μm处获得了20%的反射率。但当GeO2含量超过35%后，其IR反射率降低到几乎为零。因此，40SiO2-30TiO2-30GeO2的凝胶玻璃涂层是较理想的。     

CdS微晶掺杂TiO2—SiO2复合薄膜的非线性光学特性

采用溶胶－凝胶方法在普通的载玻片上制备了ＣｄＳ微晶掺杂的ＴｉＯ２－ＳｉＯ２复合薄膜。用正硅酸乙酯、钛酸丁酯、醋酸镉作原料，比较了硫脲和硫化乙氨的硫化作用。不同热处理温度、时间的吸收光谱表明，薄膜中存在着量子尺寸效应。采用Ｚ－Ｓｃａｎ技术测量了薄膜的非线性吸收及非线性折射率。     

高度分散有机荧光分子的SiO2凝胶膜的发光

通过溶胶凝胶法制备了不同浓度的有机荧光分子BBOT(2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene);分散的纳米多孔二氧化硅凝胶薄膜,并获得了亮蓝色发光.本工作通过光谱技术研究了薄膜的发光特性;用扫描电子显微镜(SEM)技术表征了Btg)T/SiO2薄膜的表面形貌,分析了BBOT在二氧化硅凝胶中的表观分散行为和聚集态.通过研究有机荧光分子BBOT在介电常数从2到81的几种不同介质环境中的吸收和发射光谱的变化,揭示了BBOT在二氧化硅凝胶中吸收和发射主峰位相对于其在共溶剂1,4二氧六环中红移的原因是由于BBOT分子的电子基态比其激发态极性弱、与极性较大的二氧化硅凝胶相互作用的结果.薄膜发光强度随BBOT掺杂浓度的增加而增强,在6×10-3 M时达到最强.通过SEM技术表明,在掺杂浓度6×10-3M及以下薄膜没有相分离,仅在10-2 M时出现BBOT分子聚集形成的针状结晶形貌.本研究表明杂化薄膜通过纳米多孔二氧化硅的"笼"的作用获得BBOT有机分子在二氧化硅凝胶中的高度分散而抑制其浓度猝灭,得到高强度蓝色发光.     

含螺噁嗪的SiO2变色凝胶实时全息记录光栅

通过本体溶胶-凝胶方法制备了含6′-哌啶-1,3,3-三甲基螺[吲哚-2,3-′[3H]萘-[2,1-b][1,4]噁嗪]的光活性SiO2凝胶。光栅生长曲线显示该光活性凝胶具有快速光响应。在紫外光的预激发下用He-Ne激光器写入光栅时衍射效率的变化规律显示螺噁嗪的光致变色有光致构造异构和光致顺反异构两个竞争过程。通过紫外激发光源的开启和闭合对实时全息光栅的衍射信号进行了调制。     

PPV/ SiO2 块状溶胶-凝胶材料中光学两波耦合现象的研究

本文介绍了一种由π－共轭聚合物聚对苯撑亚乙烯（PPV）均匀掺杂SiO2的块状溶胶－凝胶材料,该材料具有良好光学品质和光学加工性能。通过扫描隧道显微镜（STM）、紫外－可见吸收光谱和付氏红外光谱（FTIR）等方法研究了它的线性光学特性。在对材料进行的光学两波耦合实验中,观察到了非对称能量耦合现象,本文对此进行了分析。     

发光薄膜的制备及应用

与传统的发光粉制作的显示屏相比，发光薄膜在对比度、分辨率、热传导、均匀性、与基底的附着性、释气速率等方面都显示出较强的优越性。因此，作为功能材料，发光薄膜在诸如阴极射线管（CRTs)、电致发光显示（ELDs)及场发射显示（FEDs)等平板显示领域中有着广阔的应用前景。发光薄膜的制备方法有许多种，包括溅射法、金属有机物化学汽相沉积法、溶胶－凝胶法、脉冲激光沉积法、喷雾热解法、蒸镀法等。本文系统地对这些发光薄膜的制备方法及其应用情况作以简单的介绍，最后对发光薄膜的发展趋势进行了展望。     

Synthesis of silicon nanowires supported Ag nanoparticles and their catalytic activity in photo-degradation of Rhodamine B

Silver modified silicon nanowires were obtained and employed as photo-catalysts in the dcgradation of Rhodamine B (RhB), which demonstrated the excellent catalytic activity. These catalysts may be recycled and reused.     

纳米化处理对g-C3N4物理性质和光催化性能的影响

采用高压微射流均质处理方法,分别在水和异丙醇介质中对以三聚氰胺为前驱体通过热聚合法制备的本征g-C₃N₄材料进行纳米化处理。通过在紫外光和可见光下降解罗丹明B(RhB)和亚甲基蓝(MB),对纳米片的光催化活性进行研究。结果表明:高压微射流均质纳米化处理不会破坏g-C₃N₄层内结构,却能够有效减小g-C₃N₄的颗粒尺寸、增大其比表面积、暴露更多的活性反应位点以及延长载流子的寿命,从而提高g-C₃N₄材料的光催化活性。此外,纳米化处理能够有效调控g-C₃N₄表面官能团,使水相和异丙醇相氮化碳纳米片表面带相反的电荷,可见光照射下,当纳米化处理次数为8次时,异丙醇相氮化碳在210min内对MB的降解率为49%,水相氮化碳在210min内对RhB的降解率为100%。     

卤离子吸附竞争对罗丹明B-金胶体系NIR-SERS的影响

在金纳米胶体体系中采用近红外激光(1064nm)激发,研究了卤素离子(Cl-、Br-、I-)对激光染料 罗丹明B(RhB)分子近红外表面增强拉曼散射光谱(NIR SERS)的影响,给出了表面增强拉曼谱随卤素离子加入顺序的不同的变化过程。结果表明,在此体系中卤素离子与分子共吸附能力的强弱顺序为Cl- Br-相似文献   

Si/SiO2和SiNx/SiO2多层膜的室温光致发光

采用射频磁控溅射法,制备了纳米Si/SiO2和SiNx/SiO2多层膜,得到强的可见光致发光,利用傅里叶红外吸收(FTIR)谱和光致发光(PL)谱,对其发光特性进行了研究,在374 nm和712 nm左右观察到强发光峰.用量子限制-发光中心(QCLC)模型解释了其可能的发光机制,认为发光可能源自于SiOx界面处的缺陷发光中心.建立了发光的能隙态(EGS)模型,认为440 nm和485 nm的发光源于N-Si-O和Si-O-Si缺陷态能级.     

化学法制备的PTCR型（Sr,Pb）TiO3半导体陶瓷

采用化学共沉淀法制备（Ｓｒ１－ｘＰｂｘ）ＴｉＯ３粉末，在６０～２２０°Ｃ间获得了五种居里温度的ＰＴＣＲ型（Ｓｒ，Ｐｂ）ＴｉＯ３陶瓷。实验结果表明，材料室温电阻率低于２０Ωｃｍ，升阻比高于１０５．５。文中还给出了（Ｓｒ，Ｐｂ）ＴｉＯ３铁电体的四方→立方相转变温度（居里温度）、晶胞参数等一系列随Ｐｂ／Ｓｒ比变化的材料性质。     

Effect of TiO2 nanoparticle content in sol–gel derived TiO2 paste on the photovoltaic properties of TiO2 photoanode of dye-sensitized solar cells

In the present work, the effect of the amount of TiO₂ nanoparticles, added to the sol–gel derived paste, on the photovoltaic properties of fabricated dye-sensitized solar cells (DSSCs) was investigated. A titanium sol (Ti-sol) was synthesized using a Pechini type sol–gel method, and different pastes were prepared by adding various amounts of TiO₂ nanoparticles to the obtained Ti-sol. The pastes were used to fabricate the mesoporous TiO₂ semiconducting layers for DSSCs. It was observed that by increasing the mass ratio (MR) of TiO₂ nanoparticles to Ti-sol the thickness of TiO₂ layer increases. This led to the more adsorption of dye molecules per unit area of active TiO₂ layer, which were determined by UV–vis spectrophotometry. Also, micro-cracks were observed in TiO₂ layers obtained from pastes with low MR values. But their amount and size decreased with increasing MR, which was due to the decrease of paste surface tension (σ). As a result, short circuit current density (I_sc) showed continuous increase with increasing MR, which was due to the more dye adsorption. Open circuit voltage (V_oc) first increased and then decreased by enhancing MR, which was explained by considering the electron–hole recombination rate. Finally, the DSSC fabricated from the paste with MR=0.65 showed the maximum conversion efficiency (η).     

Fabrication of CuInS2/CNTs absorber layers by sol–gel method

In this work, CuInS₂/multiwalled carbon nanotube (MWCNT) layers are fabricated by the sol–gel spin-coating method. We introduce two forms of MWCNTs into a CIS₂ solution, washed functional multiwalled carbon nanotubes (W-FMWCNTs) and unwashed-functional multiwalled carbon nanotubes (UW-FMWCNTs), in order to investigate the effects of MWCNTs and an acidic environment on the physical properties of the CIS₂ absorber layers. The structure and morphology of the samples are investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The XRD study shows that all samples crystallize in a tetragonal structure. The results obtained from the optical, thermo-electric, and electrical measurements indicate that the two groups of CIS₂ layers prepared using W- and UW-FMWCNTs show the opposite behaviors. The Seebeck coefficient (SC) measurements indicate possible formation of a p–n junction.     

Photocatalytic degradation of RhB and TNT and photocatalytic water splitting with CZTS microparticles

Cu₂ZnSnS₄ (CZTS) is a main candidate material for solar energy conversion through both photovoltaics and photocatalysis based on environmentally friendly elements and with a direct band gap of 1.5 eV. We report the synthesis of quasi Cu₂ZnSnS₄ microparticles with unprecedented narrow size distributions. The structural, morphological and core level analysis has been carried out by XRD, SEM and XPS techniques. These microparticles have shown excellent photocatalytic activity toward degradation of Rhodamine B dye (RhB) and TNT under visible light. The extent of mineralization has been analyzed by COD and TOC values. Photocatalytic water splitting for H₂ generation has also been reported.     

Sol–gel synthesized Titania nanoparticles deposited on porous polycrystalline silicon: Improved carbon dioxide sensor properties

Titania nanoparticles (TNPs) were synthesized by a sol–gel method in our laboratory using titanium tetrachloride as the precursor and isopropanol as the solvent. The particles׳ size distribution histogram was determined using ImageJ software and the size of TNPs was obtained in the range of 7.5–10.5 nm. The nanoparticle with the average size of 8.5 nm was calculated using Scherrer׳s formula. Homogeneous and spherical nanoparticles were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and UV–visible spectroscopy (UV–vis). The X-ray powder diffraction analysis showed that the prepared sample (TNPs) has pure anatase phase. TNPs were deposited on porous polycrystalline silicon (PPS) substrate by electron beam evaporation. The TNPs thickness was 23±2 nm at 10⁻⁵ mbar pressure at room temperature. Porosity was performed by an anodization method. Since polycrystalline silicon wafers consist of different grains with different orientations, the pore size distribution in porous layer is non-uniform [1]. Therefore, the average diameter of pores can be reported in PPS layer analysis. Average diameter of pores was estimated in the range of 5 μm which was characterized by FESEM. The nanostructured thin films devices (Al/Si/PPS/TNPs/Al and Al/Si/PPS/Al) were fabricated in the sandwich form by aluminum (Al) electrodes which were also deposited by electron beam evaporation. Electrical measurements (I–V curves) demonstrated the semiconducting behavior of thin film devices. The gas sensitivity was studied on exposure to 10% CO₂ gas. As a result, conductivity of devices increased on exposure to CO₂ gas. The device with TNPs thin film (Al/Si/PPS/TNPs/Al) was more sensitive and, had better response and reversibility in comparison with the device without TNPs thin film (Al/Si/PPS/Al).