溶胶-凝胶工艺制备SrTiO3纳米薄膜的研究

采用溶胶-凝胶方法,以醋酸锶、钛酸四丁酯为前驱体,乙酰丙酮为螯合剂,乙二醇甲醚为溶剂,乙酸为助溶剂和催化剂制备溶胶,用旋涂法在Si(100)衬底上制备出了具有典型钙钛矿型结构的SrTiO3纳米薄膜.用XRD、AFM、SEM和椭圆偏光仪等手段分析了薄膜的性能,结果显示薄膜的表面均匀、无裂纹、厚度20～30nm,折射率1.75～1.85,晶粒度35～60nm,表面平均粗糙度RMS为3.4～3.8 nm,晶粒形貌呈类圆锥形态.     

溶胶–凝胶法制备BaTiO3薄膜的研究

以醋酸钡和钛酸丁酯为原料,应用溶胶–凝胶法在 Al2O3基片上制备了 BaTiO3薄膜。具体分析了原料、溶剂、催化剂、溶液的 pH 值、螯合剂和表面活性剂对溶胶–凝胶体系的影响,以及加水量、乙二醇加入量和醋酸对溶胶–凝胶黏度的影响。并且可以把掺杂离子加入到溶胶–凝胶中,为调节 BaTiO3薄膜的性能打下了良好的基础。     

锆酸铅薄膜的生长特性与表面化学态

以醋酸铅和异丙醇锆为原料，乙二醇甲醚为溶剂。通过溶胶-凝胶法和快速退火工艺在Pt(111)／Ti／SiO2／Si(100)基片成功地制备出不开裂的钙钛矿PbZrO3薄膜。用XRD和原子力显微镜测量了薄膜随退火温度变化的结构和表面形貌特征，用XPS测试了650℃退火PbZrO3薄膜的表面化学态。     

钛酸锶钡/铋锌铌多层复合薄膜的制备及性能

采用溶胶一凝胶法在Pt/Ti/SiO2/Si衬底上制备了钛酸锶钡/铋锌铌多层复合薄膜样品.研究了不同退火温度下多层复合薄膜的结构、微观形貌及介电性能.结果表明:在退火温度高于700℃时,所得复合薄膜中会出现立方焦绿石结构的铋锌铌和钙钛矿结构的钛酸锶钡.750℃退火处理得到的多层复合薄膜,表面致密,无裂纹,其相对介电常数...     

烧结温度对BaxSr1-xTiO3薄膜性能的影响

Ba、Sr0.3TiO3具有优良的介电和热释电性质，特别是可以通过改变组分来调节居里点，使其在动态随机存储器（DRAM）和红外探测器方面有着广泛的应用前景。制备薄膜的方法很多，如射频磁控贱射法、激光沉积法、化学气相沉积法、溶胶-凝胶（Sol-Gel）法等。本文用溶胶-凝胶法以乙二醇甲醚为溶剂制备出BST薄膜，并用SPM对BST薄膜进行表征，得出对薄膜进行热处理的最佳条件及掺杂对薄膜表面形象的影响。     

钛酸锶钡薄膜微细图形的制备

采用化学修饰的溶胶凝胶工艺,制备了具有紫外光感应特性的钛酸锶钡(Ba0.8Sr0.2TiO3)溶胶及其凝胶薄膜.提出了钛酸锶钡薄膜微细加工的新方法,即以苯酰丙酮(BzAcH)为化学修饰剂,乙酸钡、氯化锶、钛酸丁酯为原料,甲醇为溶剂,乳酸为催化剂,合成了具有螯合物结构的前驱溶胶体系.其螯合物的特征吸收峰在358nm附近,该溶胶及其凝胶薄膜在室温下有较好的化学稳定性;高压汞灯产生的紫外光照射可以分解薄膜中的螯合物结构,伴随着这种螯合物结构的分解,薄膜在乙醇中的溶解性迅速降低,从而表现出紫外光感应特性.利用这种光感应特性,采用紫外光通过掩膜照射薄膜,然后在乙醇中溶洗,获得了凝胶薄膜的微细图形,进一步通过600℃晶化热处理,最后得到了具有钙钛矿相结构和铁电特性的钛酸锶钡薄膜的微细图形.     

浓度对Sol-Gel法制备BST薄膜结晶及介电性能的影响

以醋酸锶、醋酸钡和钛酸四丁酯为前驱体原料,配制了不同浓度(0.05mol/L、0.1mol/L、0.3mol/L、0.4mol/L、0.5mol/L)的Ba0.65Sr0.35TiO3溶胶,采用溶胶-凝胶(Sol-Gel)和旋涂工艺,成功制备了BST薄膜.采用XRD、SEM和阻抗分析仪研究分析了前驱液浓度对BST薄膜的结晶、微观形貌和性能的影响.结果表明,在相同热处理温度下,随着前驱液浓度增加,薄膜的结晶程度、晶粒生长情况和介电常数依次提高,介电损耗降低.浓度为0.5mol/l的溶胶形成的薄膜的结晶程度较好;晶粒发育完善,晶粒与晶粒之间比较紧密,表面光滑致密无裂纹,颗粒尺寸约为60nm～80nm;且其介电性能最佳.     

ITO衬底上LiTaO3薄膜的制备与介电特性

用溶胶凝胶法在ITO衬底上制备了钽酸锂(LiTaO3)薄膜,利用XRD、SEM和AFM对薄膜的晶向、表面形态等作了表征;研究了不同溶剂对LiTaO3溶胶稳定性的影响和不同退火条件对LiTaO3薄膜结晶的影响;利用Al/LiTaO3/ITO结构,测试了薄膜的介电系数和介电损耗.结果表明:每层薄膜都晶化退火比交替使用焦化、结晶退火能生长出质量更好的LiTaO3薄膜;频率1KHz时,介电损耗约0.4,相对介电系数约53.并讨论了介电损耗增大的原因.     

PLZT薄膜的结构、介电与光学性能的研究

以硝酸镧、醋酸铅、钛酸丁酯和异丙醇锆为原料，乙二醇甲醚作溶剂。用简单的溶胶一凝胶法和快速退火工艺在Si(111)、石英和Pt／Ti／SiO2／Si(100)基片成功地制备出了高度多晶和(111)取向生长的(Pb，La)(Ti，Zr)O3(PLZT)薄膜。用原子力显微镜分析了薄膜的表面形貌；测试了薄膜的铁电和介电特性。PLZT薄膜的剩余极化强度和矫顽场分别为10．3μC／cm^2和36kV／cm；在100kHz，薄膜的介电常数和损耗因子分别为682和0．021。生长在石英基片上的薄膜具有好的透光性，当波长高于360nm，其透过率高达72％。     

水热辅助聚合物前驱体法制备铌酸钾钠薄膜

以自制氢氧化铌、化学试剂碳酸钾、碳酸钠为原料,柠檬酸(CA)为螯合剂,乙二醇(EG)为酯化剂,采用水热辅助聚合物前驱体法在SiO2/Si基板上制备了铌酸钾钠(KNN)薄膜.研究了CA和EG用量对溶胶性能的影响,衬底和退火温度对薄膜的影响.结果表明,当n(CA):n(金属离子)=3:1,n(CA):n(EG)=1:2时,可获得稳定性好的溶胶.以水热处理过的Si片为基板得到的薄膜结晶性和致密性都有了很大的改善;随着退火温度的升高,薄膜的结晶性越来越好,所得薄膜粒径均匀,无裂纹,有定向生长的趋势.     

Investigations of Indium Tin Oxide—Barium Strontium Titanate–Indium Tin Oxide Heterostructure for Tunability

This letter reports for the first time the interesting behavior of the interface between indium tin oxide (ITO) as a high resistive electrode and barium strontium titanate tunable paraelectric thin film material. The interface is consisting of barium strontium titanate (BST) thin film dielectric material sandwiched between two ITO high resistive layers, all are integrated above glass substrate. When dc field is applied between the ITO layers, the BST thin film material properties are tuned. It is found that the ITO/BST/ITO heterostructure exhibits a tunable resistor performance. To our knowledge; these results are never reported.     

钛酸锶钡(BST)铁电移相器材料的研究现状

钛酸锶钡(BST)材料被普遍认为是最有前途的铁电移相器材料。BST作为铁电移相器材料的研究已有多年,到目前为止取得了不少突破性的进展。综述了国内外研究人员在BST体材、厚膜以及薄膜方面所做的工作及获得的一些成果。     

覆有BST膜的半导体功率器件结终端研究

通过一系列的工艺步骤,在半导体功率器件含有场限环(FLR)的结终端上覆盖了一层300 nm厚、介电常数高的钛酸锶钡( BST)膜.对该新型结终端和无BST膜的传统FLR结终端的结构与性能进行了研究比较.结果表明,在覆盖BST膜后,FRL结终端的结构击穿电压提高了50％.这证明BST膜能够提高器件的击穿电压.     

Modeling of Lanthanum Strontium Manganite Ferromagnetic Thin Film Material Tunable Resistance

The knowledge of the electroactive and magnetoactive properties of the lanthanum strontium manganite (LSMO) ferromagnetic thin film materials is essential for modeling and design of their devices. The activity of these materials can be described by their electro- and magnetoresistances. Under electrostatic bias field, it is assumed that induced electric current will modify the electrical behavior of the electrode–manganite interface, resulting in the decrease of film resistance. This letter takes a close look at modeling the change of LSMO resistance with working frequency and applied bias.      

（Ba1—xSrx）TiO3薄膜的制备及性能的研究

选用Ba(C2H3O2)2、Sr(C2H3O2)2.1/2H2O和Ti（OC4H9）4为原材料,冰醋酸为催化剂,乙二醇乙醚为溶剂。用改进的溶胶－凝胶技术在Pt/Ti/SiO2/Si基片上成功地制备出钙钛型结构的（Ba1-xSrx)TiO3薄膜。该薄膜是制备铁电动态随机存储器、微波电容和非致冷红外焦平面阵列的优选材料;分析了薄膜的结构;测试了薄膜的介电和铁电性能。在室温10kHz下,（Ba0.73Sr0.27)TiO3薄膜介电系数和损耗分别为300和0．03。在室温1kHz下,（Ba0.95Sr0.05)TiO3薄膜剩余极化强度的矫顽场分别为3μC／cm^2和50kV/cm。     

钛酸锶钡(BST)薄膜的制备与应用研究进展

介绍了钛酸锶钡(BST)薄膜的四种制备方法(脉冲激光沉积、磁控溅射、溶胶–凝胶、金属有机化学气相沉积)及BST薄膜在介质移相器、动态随机存储器、热释电红外探测器、H2探测器中的应用等方面的研究进展。提出了需进一步开展的研究课题如:晶粒晶界控制、界面控制、漏电导机制、疲劳机制、非线性效应及大面积高质量薄膜的制备技术等。     

Microstructure of sputter-deposited strontium titanate films

The origin of a marked difference in a dielectric constant, κ, observed between two types of strontium titanium oxide (STO) films sputter-deposited on platinum layers was investigated using a transmission electron microscopy method. The first type of STO films having a low κ value initially grew as an amorphous phase, followed by the formation of a randomly oriented polycrystalline phase. The second type with a high κ, on the other hand, not only grew as a crystalline phase throughout the entire film thickness, but also exhibited a strong [111] fiber texture. The observed difference in κ between these two types of STO films can thus be explained in terms of the degree of film crystallinity and texture.     

生长时间对氧化锌纳米杆形貌的影响

采用旋涂法在洗净的玻璃衬底上制备了醋酸锌薄膜,并进一步在空气中退火获得了氧化锌(ZnO)薄膜,X射线衍射分析显示退火后获得的ZnO薄膜具有c轴(002)择优取向生长特性.通过水热法以ZnO薄膜为种子层,生长了ZnO纳米杆阵列.研究了在相同的ZnO种子层、前驱液浓度和生长温度条件下,不同生长时间对ZnO纳米杆形貌的影响.扫描电子显微镜照片显示,随着生长时间的增加,ZnO纳米杆阵列的生长具有阶段性规律,并且在经过52h生长后得到了顶端中心被溶解的ZnO纳米管.分析认为该现象和前驱液中Zn2+离子和OH-离子的浓度变化有关,同时也和ZnO的非极性结构有关.     

Electrochemical synthesis of a double‐layer film of ZnO nanosheets/nanoparticles and its application for dye‐sensitized solar cells

A double‐layer film, consisting of an upper layer of ZnO nanosheets and a lower layer of ZnO nanoparticles (designated as ZnONS/NP), was synthesized for the photoanode of a dye‐sensitized solar cell (DSSC) by a one‐step potentiostatic electrodeposition on a conducting fluorine‐doped tin oxide substrate at 70 °C in a solution containing zinc nitrate and sodium acetate, followed by the pyrolysis of the film at 300 °C. The growth mechanism of the double‐layer nanostructure was studied by monitoring the morphological changes at various periods of electrodeposition. The effects of the concentration of acetate anion on the morphology of the double‐layer structure were also studied. The double‐layer film of ZnONS/NP showed a better self‐established light scattering property, compared with that of a thin film of ZnO nanoparticles, prepared without acetate anion. The concentration of an acetate anion in the electrolyte for the electrodeposition of the double‐layer film, the electrodeposition period, and the period for dye adsorption were optimized for obtaining the best performance for a DSSC with a photoanode consisting of the double layer. A metal‐free dye, coded as D149, was used in this research. A conversion efficiency of 4.65% was achieved for a DSSC (0.2376 cm²) with the photoanode, consisting of the double‐layer film, under 100 mW/cm² illumination in the wavelength range of 400–800 nm. X‐ray diffraction patterns, thermo gravimetric curves, elemental analysis, scanning electron microscopic images, transmission electron microscopic image, transmission spectra, and electrochemical impedance spectra were used to explain observations. Copyright © 2012 John Wiley & Sons, Ltd.