Film thickness effects on nanorods organic films of azo quinoline derivatives for optical applications

The effect of film thickness on the structural and optical properties of bisbenzimidazo [2,1-a:2′,1′-a′] anthrax [2,1,9-def:6,5,10-d′e′f′] diisoquinoline-10,21-dione (BI-diisoQ) films was carried out. The morphology of BI-diisoQ film showed a definite shape of a nanorod with a length of around 5 μm and a diameter of approximately 20 nm. Also, X-ray diffraction patterns demonstrated that BI-diisoQ thin films are characterized by a mixture of amorphous and crystalline structure, whereas the phase-nature crystallization of BI-diisoQ film enhanced as the film thickness increased. The investigation of the absorption coefficient of BI-diisoQ films revealed two indirect allowed band gaps energy. The calculated values of nonlinear optical parameters for BI-diisoQ film were observed to be increased with the increase of film thickness. The optical properties of BI-diisoQ nanorod films indicated that these films have appropriate optical properties, and thus it can be recommended as a promised candidate material in superconductors, optoelectronic and photonic applications.     

Effect of chlorine doping on the structural, morphological, optical and electrical properties of spray deposited CdS thin films

CdS and chlorine doped CdS(CdS:Cl) thin films with different Cl-doping levels(0,2,4,6 and 8 at%) have been deposited on glass substrates by a spray pyrolysis technique using a perfume atomizer.The effect of Cl doping on the structural,morphological,optical and electrical properties of the films was investigated.XRD patterns revealed that all the films exhibit hexagonal crystal structure with a preferential orientation along the(0 0 2) plane irrespective of the Cl doping level.The particle size value decreases from 22.03 nm to 18.12 nm with increase in Cl concentration.Optical band gap is blue-shifted from 2.48 eV to 2.73 eV with increase in Cl doping concentration.All the films have resistivity in the order of 10~4 Ω cm.The obtained results confirm that chlorine as an anionic dopant material can enhance the physical properties of CdS thin films to a large extent.     

Structural and optical properties of Cr doped ZnO crystalline thin films deposited by reactive electron beam evaporation technique

ZnO and Cr-doped ZnO thin films are grown on to glass substrates using reactive electron beam(e-beam) evaporation technique.Variation of structural,morphological,and optical properties with Cr doping is investigated.X-ray diffraction(XRD) studies show that the films are polycrystalline in nature with single phase.Energy dispersive spectroscopy(EDS) results demonstrate that Cr ions are substitutionally incorporated into ZnO.Atomic force microscopy(AFM) reveals that the films present a compact surface and root mean squared(RMS) roughness increased with Cr contents.The optical band gap energy Eg of the films has been determined using Transmission data by spectrophotometer and ellipsometry.The band gap energy found to be decreased with increasing Cr doping concentration.The optical constants(refractive index,extinction coefficient) are calculated using ellipsometry and found to increase with Cr doping concentration.     

Ag-聚酯复合薄膜的微结构与光学性能研究

用匀胶机在载玻片上甩制5%的硅酸乙酯薄膜,在该薄膜上用磁控溅射法溅射Ag制备半连续的纳米微粒Ag薄膜,经过不同温度下的退火,处于膜表面的Ag颗粒的扩散运动增强,从而得以渗入高分子聚酯层形成Ag-聚酯复合薄膜.采用X射线衍射和紫外-可见光谱等检测手段对其微结构和光学性能进行测试与分析发现:随着退火温度的增加,Ag晶粒的晶化现象越来越明显,平均晶粒尺寸和晶格常数均呈增大趋势.随着Ag质量分数的增加,Ag的XRD衍射峰出现并逐渐增强,Ag纳米颗粒表面等离子体共振吸收峰位置逐渐红移并逐渐增强.     

Optical properties of cobalt xanthate films on different substrates

Cobalt isopropyl xanthate thin films (CXTFs) were deposited via chemical bath deposition onto different substrates: commercial glass (CG), indium tin oxide (ITO), and poly(methyl methacrylate) (PMM). Isopropyl xanthate was synthesized according to a method described in the literature. The cobalt nitrate and isopropyl xanthate were mixed in a beaker, which allowed the thin films to be deposited via a simple ion-ion mechanism. The transmission, reflectivity, refractive index, dielectric constant, and optical conductivity were investigated for various thin films coated onto different substrates. An ultraviolet-visible spectrophotometer was used to measure the optical properties of the thin films. The lowest value of the transmission and the highest value of the refractive index were observed for the thin films deposited onto PMM. The structure of the cobalt xanthate was characterized by Fourier transform infrared (FTIR) spectroscopy, which was measured using a Perkin-Elmer Spectrum 400 spectrometer. The stretching vibration of the Co-S bonds was observed at 359 cm-1 in the FTIR spectrum of the CXTFs.     

nc-Si:H薄膜的微结构特征与光学特性

利用射频等离子体增强型化学气相沉积(RF-PECVD)工艺,以SiH4和H2作为反应气体源,在玻璃和石英衬底上制备了氢化纳米晶硅(nc-Si:H)薄膜.采用Raman散射谱、原子力显微镜(AFM)、透射光谱方法对在不同衬底温度与不同H2稀释比条件下沉积生长薄膜的微结构和光学特性进行了实验研究.结果表明,nc-Si:H薄膜的晶粒尺寸为2.6～7.0nm和晶化率为45%～48%.在一定反应压强、衬底温度和射频功率下,随着H2稀释比的增加,薄膜的沉积速率降低,但晶化率和晶粒尺寸均有所增加,相应光学吸收系数增大.而在一定反应压强、射频功率和H2稀释比下,随着衬底温度的增加,沉积速率增加,薄膜晶化率提高.     

化学计量对Ba1-xSrxTiO3薄膜介电性能的影响

采用脉冲激光沉积法，在Pt／Ti／SiO2／Si衬底上制备了Ba1-xSrxTiO3薄膜，通过改变Sr化学计量，研究了其介电性质．实验结果发现：随着Sr化学计量的增加，薄膜的介电系数明显增大，而损耗仍然保持在较低的水平．研究表明：薄膜介电系数的增大是由于薄膜中颗粒尺寸的减小，导致了居里温度的降低．另外，C-V特性研究发现：随着Sr化学计量的增加，薄膜的电容调谐度也有所提高．     

NixCu1-x复合团簇镶嵌薄膜的微结构和磁特性

用直流磁控溅射的方法在室温Si基片上制备体积百分比分别为5%,10%,20%,40%的系列Ni Cu磁性复合团簇镶嵌薄膜样品,并利用X射线衍射技术、振动样品磁强计等方法对团簇的微结构和磁性能进行了测试研究。微结构分析表明:薄膜呈多晶状态,晶体结构仍为面心立方,随着Ni组份的增加,复合团簇膜的晶粒尺寸与平均晶格常数均减小。磁性分析表明:所有样品均表现出铁磁性,随着Ni百分比含量的增加,矫顽力Hc减小,饱和磁化强度MS增加,磁性逐渐增强,且尺寸效应明显。     

有序分子膜的摩擦学特性研究进展

有序分子膜优良的润滑性能使其在解决摩擦学问题中有潜在的应用价值。文中论述了有关Langmuir Blodgett(LB)膜、自组装 (SA)膜和分子沉积 (MD)膜在实验研究及理论研究方面取得的进展 ,介绍了 3种有序分子膜各自的特点及其摩擦学性能的影响因素。目前对LB膜的研究最广泛 ,对SA膜和MD膜的研究起步较晚 ,并对它们性能的优缺点进行了比较 ,同时对有序分子膜在纳米摩擦学方面的应用前景进行了分析。     

Influence of growth conditions on the electrochemical synthesis of SnS thin films and their optical properties

Tin sulfide (SnS) thin films were prepared by electrodeposition onto fluorine-doped tin oxide (FTO) glass substrates using an aqueous solution containing SnCl₂ and Na₂S₂O₃ at various deposition potentials (E) and bath concentrations. The pH value and temperature of the solution were kept constant. The deposited films were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), photoluminescence (PL), and ultraviolet–visible (UV–Vis) spectroscopy. The FESEM images demonstrated that changes in the deposition potential (E) and solution concentration led to marked changes in the morphology of the deposited SnS films. Energy-dispersive X-ray analysis (EDXA) results showed that the Sn/S atomic ratio strongly depended on both the solution concentration and the deposition potential. To obtain an Sn/S atomic ratio approximately equal to 1, the optimal Sn2+/S₂O₃2- molar ratio and E parameter were 1/8 and -1.0 V, respectively. The XRD patterns showed that the synthesized SnS was obviously polycrystalline, with an orthorhombic structure. The effects of the variations of bath concentration and deposition potential on the band-gap energy (E_g) were studied using PL and UV–Vis experiments. The PL spectra of all the SnS films contained two peaks in the visible region and one peak in the infrared (IR) region. The UV–Vis spectra showed that the optical band-gap energy varies from 1.21 to 1.44 eV.     

RF磁控溅射沉积压强对InGaZnO4薄膜特性的影响

采用射频(RF)磁控溅射沉积方法,在室温不同压强下在石英玻璃衬底上制备出高透光率与较好电学性质的透明氧化物半导体InGaZnO4(IGZO)薄膜,并对薄膜进行X线衍射(XRD)、生长速率、电阻率和透光率的测试与表征.结果表明,实验所获样品IGZO薄膜为非晶态,薄膜最小电阻率为1.3×10-3Ω·cm,根据光学性能测试结果,IGZO薄膜在200～350 nm的紫外光区有较强吸收,在400～900 nm的可见光波段的透过率为75％～97％.     

PLD法制备BST薄膜及其介电性能研究

采用脉冲激光沉积法制备Ba_(0.6)Sr_(0.4)TiO_3(BST)薄膜;研究不同氧压下的BST薄膜的介电性能.结果表明,当沉积温度为680℃时不同氧压下的BST薄膜均择优(210)面取向生长;氧压为0.01Pa时取向因子稍大,为0.6637;当氧压从0.1 Pa变化到0.001 Pa时薄膜的平均粒径增大.介电常数增大.     

采用MBDM法获得高性能高分子膜的研究

采用多束动态混合法在３０４不锈钢样品表面成功地制备出ＰＴＦＥ（聚四氟乙烯）和ＰＥＥＫ（聚醚醚酮）混合的高性能高分子复合膜，共结合力约７０Ｎ，耐蚀能力提高２０倍，摩擦系数达到０．０７￣０．１４，比授能吸收剂量在于１０＾６Ｇｙ。     

热处理对ITO薄膜光电性能和抗蚀刻性的影响

利用不同的热处理温度对磁控溅射在玻璃基底的ITO薄膜进行退火处理.借助于原子力显微镜(AFM)、分光辐射计、四探针电阻测试仪等测试手段对不同热处理后的ITO薄膜样品进行表征,研究了不同热处理温度对ITO薄膜表面形貌、面电阻、透光率及抗刻蚀性能的影响.结果表明,随着退火温度的升高,ITO薄膜表面粗糙度增加,面电阻增大,在可见光区的透光率变大,耐刻蚀性增强.     

纳米硅/P3HT复合薄膜的制备及光学特性

采用等离子体增强化学气相沉积技术和旋涂法相结合制备了纳米硅/P3HT复合薄膜.利用Raman散射、紫外-可见吸收光谱(UV-Vis)和光致发光谱(PL)等技术对复合薄膜的微观结构及光学特性进行了分析.结果表明:氢流量的增加,可以有效钝化硅中的缺陷,提高纳米硅薄膜的晶化度;复合薄膜中纳米硅的引入改善了P3HT在短波长范围的吸收能力,但存在与P3HT辐射发光相竞争的过程;对复合薄膜的光致发光机制进行了分析.     

PbF2电子和光学性质的第一性原理研究

基于密度泛函理论, 采用赝势平面波方法研究了立方萤石结构PbF2的电子和光学性质. 基态下, 晶格常数a, 体积弹性模量B0与实验值和其他理论计算值一致. 通过其能带的研究, 发现立方萤石结构PbF2是一种直接帯隙绝缘体材料, 禁带宽度为4.41eV. 密立根电荷布居数和重叠集居数显示, 电子从Pb向F转移, 电荷主要集聚在Pb F键方向, 且PbF2是一种共价键与离子键共存的化合物. 为了更进一步的研究PbF2的光学性质, 本文还计算了PbF2的介电性质、吸收系数、复折射率、能量损失谱以及反射率. 结果表明: PbF2的主要吸收光区位于紫外光区, PbF2是一种优良的紫外光学材料.     

Nd掺杂BST薄膜的微结构与光学特性研究

用改进的溶胶-凝胶技术,在硅和石英衬底上制备了不同浓度的Nd掺杂Ba0.80Sr0.20TiO3薄膜,应用XRD和SEM表征了薄膜的晶化行为和微观形貌.测试发现700℃退火后,薄膜晶化情况良好,具有典型的多晶钙钛矿结构,表面致密,无裂纹和孔洞,晶粒生长均匀,随着Nd掺杂量的增加,晶粒尺寸逐渐减小.在200~1 000 nm的波长范围内测试了薄膜的透射谱,用"包络法"计算了薄膜的折射率,薄膜折射率与波长呈现典型的电子带间跃迁的色散关系,波长为400 nm时,1%Nd(按物质的量计算百分比)掺杂的BST薄膜的折射率为2.06,小于纯BST薄膜的折射率2.10,这是由于Nd掺杂引起薄膜内部应力变化造成薄膜折射率降低.由吸收谱和Tauc关系确定了Nd掺杂对薄膜的光学带隙的影响.     

可食性甲基纤维素复合膜的制备及性能研究

以甲基纤维素(M C)作为基本的成膜物质制备M C膜,在此基础上通过添加其它物质制备出M C复合膜.用抗张强度(TS)、伸长率(E)和水蒸气透过系数(fW)等性能指标评价膜的性能,并确定各种添加物质的最佳添加量,得到性能较好的M C复合膜.     

Microstructures and optical properties of sol-gel derived TiO2 anatase thin films

TiO₂ anatase thin films on quartz substrates were prepared with sol-gel method. The dry gel films, made by spin coating 10 times, were calcined at various temperatures. From X-ray diffraction analyses, it is found that the anatase to rutile phase transformation temperature of the films is higher than 850°C, the films are preferentially oriented on (0 0 1) plane, i. e.c-axis oriented. The thickness, refractive indexes, absorption coefficients and extinction coefficients of the films were determined from UV-Vis transmission spectra of the films using a UV-Vis spectrophotometer. The thickness of the films is about 570 nm. The refractive indexes, absorption coefficients and the extinction coefficients of the present films are larger than the values of anatase films prepared by sputtering. This indicates that the films made with sol-gel method are very dense. Biography: LIU Zhong-chi(1967-), male, Master candidate. Research direction: non-linear optical materials.     

掺杂与应力对ZrO2薄膜电子结构和光学性质的影响

利用基于密度泛函理论的第一性原理平面波超软赝势方法系统地研究了掺杂和应力对ZrO_2薄膜的电子结构与光学性质的影响.本文首先研究了Hf原子替代掺杂对ZrO_2薄膜物性的影响,研究结果表明,Hf原子掺杂减小了ZrO_2薄膜的带隙和态密度大小,可在一定程度上降低其表面缺陷电荷和漏电流.掺杂Hf原子后介电峰和吸收峰的值明显下降,同时介电峰和吸收峰的波形均出现了窄化现象,半高宽显著减小.本文也着重研究了不同应力下四方晶相ZrO_2薄膜物理性质变化及规律.研究发现压应力显著调控了ZrO_2薄膜的带隙以及价带顶和导带底附近的能带结构.施加应力后吸收峰的吸收范围和强度均显著增大,峰值对应的光子能量蓝移则表明对紫外光的吸收随着应力的增加有所增强.在低能量红外和可见光区域,施加压应力后ZrO_2薄膜的折射率变大,但在紫外线区域,压应力使ZrO_2薄膜的折射率呈现出先增大后减小的波动特性.上述研究结果为ZrO_2薄膜材料的设计与应用提供了理论依据.