热致NiOx薄膜的结构和光学性质变化

利用直流磁控反应溅射技术制备了氧气和氩气的分压比为5∶100的NiOx薄膜。利用X射线衍射仪(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)和光谱仪研究了热处理对薄膜的微观结构和光学性质的影响,并对沉积态薄膜的粉末进行了热分析。沉积态的NiOx薄膜在262℃时开始分解,导致NiOx薄膜的透过率增加和反射率降低。X射线衍射和示差扫描量热曲线(DSC)分析表明,在热处理过程中并无物相的变化,光学性质的变化是由于NiOx薄膜热分解引起薄膜表面形貌发生变化而引起的。通过Kissinger公式计算出热分解所需克服的活化能为230.46kJ/mol,显示出很好的热稳定性。NiOx薄膜的热稳定性和热处理前后在波长为405nm处高的反射率差值,使其很有可能成为可录蓝光光盘的记录介质。     

Cd0.8Zn0.2S 薄膜的结构和光学性质

采用真空共蒸发法在玻璃衬底上制备了Cd1-xZnxS薄膜,并用XRD、XRF以及光学透射谱对刚沉积薄膜的结构、组分和光学性质进行了表征。刚沉积的薄膜为六方结构,沿(002) 择优取向。XRF测试结果表明石英振荡法监控的薄膜组分与XRF 获得的结果非常好地吻合。由Cd0.8Zn0.2S薄膜的光学透射谱,通过Swanepoel 原理与Wemple- DiDomenico 单振子模型,推导出薄膜的光学参量,如折射率、单振子能量、色散能、吸收系数、光学能隙等。     

Structural and optical properties of Cd_(0.8)Zn_(0.2)S thin films

Cd_(1-x)Zn_xS thin films were deposited on glass substrates by a vacuum coevaporation method.The structural,compositional,and optical properties of as-deposited Cd_(0.8)Zn_(0.2)S films were investigated using X-ray diffraction(XRD),X-ray fluorescence(XRF),X-ray photoelectron spectroscopy(XPS),and optical transmittance spectrum.The thin films are hexagonal in structure,with strong preferential orientation along the(002) planes.The composition of Cd_(1-x)Zn_xS thin films monitored by a quartz crystal oscil...     

无机络合溶胶-凝胶法制备多孔ZnO薄膜

利用无机络合溶胶-凝胶法制备多孔ZnO薄膜,同时利用多种测试手段对薄膜的晶体结构、表面形貌、多孔和光学性能进行了研究.XRD和SEM的测试结果表明,ZnO薄膜的晶体结构为六方纤锌矿,薄膜表面呈多孔状.由孔径分布曲线得出薄膜的孔主要集中在介孔2.02nm和4.97nm;500℃煅烧得到的ZnO薄膜的比表面积是27.57m2/g;在不同温度下煅烧的薄膜在可见光区域透射率均高于85%,光学带宽为3.25eV.     

热蒸发紫外LaF3薄膜光学性能和结构表征

在不同的沉积温度下,用热蒸发方法在熔融石英(JGS1)上制备了LaF3单层薄膜。分别采用分光光度计测量了薄膜样品的透射率和反射率光谱,反演得出薄膜的折射率和消光系数;采用原子力显微镜(AFM)观察了样品的表面形貌,并通过表面粗糙度计算得出总积分散射损耗;采用X射线衍射仪(XRD)测试了薄膜的晶体结构,由衍射谱图拟合得到衍射峰的半峰全宽,进而计算出薄膜晶粒的平均尺寸。实验结果表明,随着沉积温度的升高,LaF3薄膜的结晶状况明显变好,晶粒尺寸逐渐变大,膜层变得更加致密,薄膜的光学常数和折射率不均匀性均呈线性变化。沉积温度的增加对薄膜表面粗糙度的影响不明显,散射损耗在光学损耗中所占比例较小,所以光学损耗的变化主要由吸收损耗引起。     

Ca0.28Ba0.72Nb2O6单晶的光学性质的研究

研究了室温下铌酸钙钡单晶的光学性质。分别用分光光度计和椭偏光谱仪测量了铌酸钙钡晶体的透射率和折射率随波长的变化关系，结果表明铌酸钙钡晶体具有正常色散关系，且寻常光折射率‰大于异常光折射率ne，说明该晶体为负的单轴晶。折射率之差在短波区达到0．12。透射率光谱显示该晶体在400～900nm波段是透明的。根据透射率计算了该波段晶体的吸收系数以及它的平方根。通过对该曲线的研究，发现铌酸钙钡晶体吸收边以下对应的跃迁为间接跃迁，计算出间接跃迁的禁带宽度E为2．94eV以及声子能量E为0．17eV。此外，通过改变系统光路中偏振片的透振方向，获得了寻常光和异常光的透射率，并进一步计算了它们的吸收系数。     

物理技术与方法在溶致液晶结构研究中的应用

现代物理技术与方法的发展为液晶科学的研究提供了丰富的手段。文章介绍了在溶致液晶研究中的一些常用物理技术与方法如偏光显微镜、量热法、X射线，同时重点介绍了一些新兴的非常规研究手段诸如中子散射技术、光谱技术、电子显微镜、扫描探针显微镜(扫描隧道显微镜、原子力显微镜)。并对诸多技术与方法近年来在国内外的应用进展做了简单介绍，且对各种技术与方法的优缺点进行了类比。     

基于Y缺陷的改进型光子晶体光分路器

提出一种Y缺陷的改进型光子晶体光分路器,以提高输出端的透射率。在完整的二维光子晶体中引入线缺陷,构成1×4的Y型光子晶体光分路器。通过调节第一分支处的4个介质柱的半径,使其每个输出端口具有更高的透射率。同时,通过改变第二分支处的1个介质柱的半径,可以实现输出端口的高透射率和输出光能量的灵活调节。Y缺陷光子晶体光分路器可以广泛应用于未来的光路集成、集成光学、微光信息处理和光通信领域。     

氧分压对脉冲激光沉积β-Ga2O3-δ薄膜光学性能的影响

在不同氧分压下,用脉冲激光沉积法在c-蓝宝石衬底上制备了高质量β-Ga₂O_3?δ薄膜。通过X-射线衍射、远红外反射光谱、X-射线光电子能谱和紫外-可见-近红外透射光谱系统地研究了β-Ga₂O_3?δ薄膜的晶格结构、化学计量比和光学性质。X-射线衍射分析表明,所有沉积的薄膜以(-201)晶向方向生长。透射光谱显示薄膜在255 nm以上的紫外-可见-近红外波段具有80%以上的高透明度,同时在255 nm附近有一个陡峭的吸收边。此外,利用Tauc-Lorentz(TL)色散函数模型和Tauc公式,我们提取了β-Ga₂O_3?δ薄膜的光学常数和光学直接带隙。更进一步,我们通过理论计算解释了氧气分压对β-Ga₂O_3?δ薄膜光学性质的影响。     

新型长波红外非线性晶体PbIn6Te10的生长

新型长波红外非线性晶体PbIn6Te10具有透光波段宽(1.3~31μm)、非线性系数大(d11=51 pm/V),双折射适宜(~0.05)等优点,在14~25μm乃至25μm以上波段具有较大应用潜力。文中通过相图分析结合具体实验,筛选出较合适的组分配比,并采用高温单温区法合成多晶,布里奇曼法生长出尺寸φ11 mm×55 mm的单晶棒。对生长的PbIn6Te10晶体进行X射线衍射、摇摆曲线、透过率等测试,结果表明,晶体为三方结构,晶格常格为a=b=1.496 1 nm,c=1.825 7 nm,生长出的单晶结晶性较好,半高宽(FHWM)约0.253°,2.5~25μm波段晶体的平均透过率在50%以上,对应收系数处于0.3~0.6 cm-1之间。     

Optoelectrical Behavior of Ferroelectric Lithium Rubidium Sulfate Crystals

Single crystals of lithium rubidium sulfate with good transparency have been grown from aqueous solution by a slow evaporation technique. Single-crystal x-ray diffraction results revealed that, at room temperature, the crystal belongs to the monoclinic system in space group P2₁/n. From the transmittance and reflectance spectra, various optoelectrical constants such as the refractive index, extinction coefficient, optical bandgap for direct transition, optical conductivity, electronic polarizability, high-frequency dielectric constant, and optical electronegativity were calculated for the investigated lithium rubidium sulfate crystal. A correlation between the various optical parameters was also observed. The refractive index was fit to a three-term Cauchy dispersion relationship. The single-oscillator Wemple–DiDomenico model was applied to discuss the dispersion of the refractive index. The optical transmittance study revealed transparency of the crystal in the entire visible region with wide optical bandgap. The electronic polarizability values calculated from the Clausius–Mossotti equation and from bandgap analysis were found to be in good agreement.     

Durability of polymeric encapsulation materials in a PMMA/glass concentrator photovoltaic system

The durability of polymeric encapsulation materials was examined using outdoor exposure at the nominal geometric concentration of 500 suns. The results for 36‐month cumulative field deployment are presented for materials including: poly(ethylene‐co‐vinyl acetate), (EVA); polyvinyl butyral (PVB); ionomer; polyethylene/polyoctene copolymer (PO); thermoplastic polyurethane (TPU); poly(dimethylsiloxane) (PDMS); poly(diphenyl dimethyl siloxane) (PDPDMS); and poly(phenyl‐methyl siloxane) (PPMS). Measurements of the field conditions including ambient temperature and ultraviolet (UV) dose were recorded at the test site during the experiment. Measurements for the experiment included optical transmittance (with subsequent analysis of solar‐weighted transmittance, UV cut‐off wavelength, and yellowness index), mass, visual photography, photoelastic imaging, and fluorescence spectroscopy. While the results to date for EVA are presented and discussed, examination here focuses more on the siloxane materials. A specimen recently observed to fail by thermal decomposition is discussed in terms of the implementation of the experiment as well as its fluorescence signature, which was observed to become more pronounced with age. Modulated thermogravimetry (allowing determination of the activation energy of thermal decomposition) was performed on a subset of the siloxanes to quantify the propensity for decomposition at elevated temperatures. Supplemental, Pt‐catalyst‐ and primer‐solutions as well as peroxide‐cured PDMS specimens were examined to assess the source of the luminescence. The results of the study including the change in optical transmittance, observed failure modes, and subsequent analyses of the failure modes are described in the conclusions. Copyright © 2016 John Wiley & Sons, Ltd.     

基板表面锚泊对液晶全漏导模影响的理论研究

平行排列向列相液晶盒基板表面锚泊能可以影响液晶盒内液晶分子指向矢的分布,光学上将导致液晶导模结构的变化。为了研究基板表面锚泊对液晶全漏导模的影响,首先基于液晶弹性理论推导了液晶指向矢在外加电压下满足的平衡态方程,随后由差分迭代方法数值计算液晶指向矢。最后,基于液晶多层光学理论推导了液晶导波反射率和透射率公式,并通过数值计算得到了平行排列向列相液晶全漏波导反射率Rss随内角变化的理论曲线。计算结果表明,相对于强锚泊情形(1×10~(-3) J/m~2),不同锚泊能强度(5×10~(-5) J/m~2～1×10~(-3) J/m~2)下的理论曲线会发生左移现象,移动距离与锚泊能强度有关。由曲线移动的距离可以确定液晶盒基板表面锚泊能的强度。该研究为进一步利用光导波技术测量液晶盒基板表面锚泊能强度提供了理论依据。     

PDLC膜的光学特性

应用光学基本原理对聚合物分散液晶(PDLC)膜的光学特性进行描述,分析聚合物分散液晶微滴中液晶分子排列方式与液晶折射率的关系,并介绍表征PDLC膜散射本领的重要参数的雾度概念及雾度测试方法和表征PDLC膜透光本领的重要参数的透光率概念及透光率的测试方法。     

脉冲激光沉积法制备红外光学SiC薄膜特性研究

采用脉冲激光沉积法在锗基底制备无氢SiC薄膜,研究了激光能量对SiC薄膜显微结构、成分和红外光学性能的影响规律。利用傅里叶红外光谱仪测量了锗基底SiC薄膜样品的红外透射光谱,其在785 cm-1附近有一个强烈Si-C键特征吸收峰,并在红外波数4 000~1 300 cm-1之间具有良好的透过性。通过对透射光谱拟合计算可知:在红外波段2.5~7.7 m之间,SiC薄膜的折射率和消光系数均随着激光能量的增加而增大,折射率大约从2.15上升到2.33,激光能量从400 mJ增加到600 mJ,且当激光能量为400、500 mJ时,消光系数均在10-3量级以内,光学吸收很小。研究表明,SiC薄膜在红外2.5~7.7 m波段是一种优异的光学薄膜材料。     

热处理对低损耗高反膜特性的影响分析

低损耗激光薄膜反射镜是环形激光器谐振腔的关键元件之一,首先设计和制备了工作角度为45的低损耗高反膜。为了提高低损耗高反膜的光学性能,采用高温热处理的方式,研究了热处理对低损耗高反膜的透射率、散射系数、表面粗糙度、相移等特性的影响。高温热处理对高反膜的散射系数、表面粗糙度影响较小,随着热处理温度的增加,高反膜相移逐渐降低。当退火温度为550 ℃时,环形激光器输出性能稳定性最好,当工作230 h 后,输出能量仅下降到初始值的90.5%。实验结果表明,采用合适的热处理方式,可以有效改善低损耗高反膜特性以及环形激光器的输出性能。     

Effect of Bi doping on the properties of CdSe thin films for optoelectronic device applications

CdSe and Bi (1%, 2%, 3%) doped CdSe thin films were deposited on the glass substrates using thermal evaporation technique. Effect of Bi doping on the structural, optical, electrical and photo response properties of CdSe thin films were investigated. The X-ray diffraction studies reveals that undoped and Bi doped CdSe films are polycrystalline in nature with hexagonal crystal structure along (002) direction. No significant changes are observed in the lattice parameters or the grain size indicating minimum lattice distortion. The optical band gap of undoped CdSe film was estimated to be 1.67 eV. Replacement of cadmium by bismuth results in an increase in the electrical conductivity of doped films. Doping with bismuth is found to improve the photo sensitivity of CdSe thin films.     

金属-碳复合材料的制备及其非线性光学性质研究

基于浸渍法,成功制备了铁含量为10.7 wt％、铜含量为12.9 wt％的金属-碳复合材料,通过扫描电子显微镜、X射线粉末衍射谱、电感耦合等离子体原子发射光谱等手段表征了金属-碳复合材料的结构、形貌、晶型以及元素组成.通过开孔Z扫描实验和光限幅实验对该材料的非线性光学性质进行测试,该材料表现出优秀的反饱和吸收型非线性光...     

Growth and molarity effects on properties of alumina thin films obtained by spray pyrolysis

Various and versatile applications of alumina in materials science and engineering specially in semiconductor and energy conversion technology encouraged us to prepare and investigate its physical properties as much as possible. Hence, after depositing of alumina thin films on glass substrates by a spray pyrolysis technique, structural, morphological, and optical properties of the films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and UV–visible spectrophotometry. Different optical quantities, such as optical band gap, refractive index and extinction coefficient, were determined in this article for different molarities (from 0.10 M to 0.25 M) at two specific substrate temperatures (250 °C and 500 °C). XRD results showed the prevailing amorphous phase in all samples as expected, whereas SEM, XPS, and FTIR presented the presence of molarity effects on alumina properties. Decrease of optical transmittance with molarity increase was notable. Using the transmittance data other optical quantities were obtained by a numerical approximation method.     

晶向对SnO2:F透明导电玻璃特性的影响

本文利用超声喷雾法制备了SnO2:F透明导电薄膜,snCl4·5H2O与NH4F分别用作锡源与氟掺杂,玻璃衬底温度控制在360℃.X射线衍射仪、扫描电镜、紫外可见分光光度计与四探针仪分别用于表征样品的晶体结构、表面形貌、透光率与面电阻.研究结果表明:超声喷雾沉积的SnO2:F薄膜主要为四方晶系的多晶薄膜,并且随着沉积条件的改变,在(110)、(220)晶向出现不同程度的择优取向,其中在(200)晶向上择优取向生长的薄膜面电阻明显低于(110)晶向,最低可达到5 Ω/□,所有样品透光率都较高,在450～1000 nm范围内的平均透光率可达到80～90%.