共查询到19条相似文献,搜索用时 109 毫秒
1.
以硝酸镉、硫脲和正硅酸乙酯为前驱体, 采用电化学-溶胶凝胶法, 以ITO玻璃为基底制备了透明薄膜。扫描电子显微镜(SEM)表征表明薄膜为纳米束结构。X射线能谱(EDX)表征表明薄膜由Si、O、Cd、S元素组成, Cd/S(原子比)>1。EDX表征结合循环伏安(CV)实验确定薄膜为Cd/CdS-SiO2复合薄膜。Z扫描表征表明, 薄膜在1064 nm处表现出自散焦特性的非线性折射效应和饱和吸收特性的非线性吸收特性。薄膜的三阶非线性极化率(χ(3))较高, 达到了1.18×10-14~1.39×10-13 (m/V)2, 表明薄膜具有优良的三阶光学非线性。分析认为薄膜中CdS的含量对薄膜的光学性非线性起主要作用。 相似文献
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以正硅酸乙酯、硼酸、金属钠为前驱体采用溶胶-凝胶法合成含Ag量子点的钠硼硅玻璃。X射线粉末衍射 (XRD) 分析Ag量子点具有立方相。通过透射电子显微镜 (TEM) 和高分辨透射电子显微镜 (HRTEM) 测定量子点的尺寸和分布, 结果显示在玻璃中量子点呈规则的球形, 并且尺寸在5~13 nm之间。紫外-可见(UV-Vis)吸收光谱仪得到Ag量子点的表面等离子体共振吸收峰大约在406 nm附近; 利用飞秒Z-scan 技术在800 nm波长处用飞秒钛宝石激光辐照对Ag量子点玻璃的非线性光学性质进行研究, 该玻璃的非线性折射率γ、非线性吸收系数β和三阶非线性极化率χ(3)分别为 –1.72×10-17 m2/W、9.96×10-11 m/W、1.01×10-11 esu。 相似文献
3.
采用真空蒸发法制备了4-硝基-4-二甲基氨基偶氮苯 (Azo) 薄膜, 研究了蒸发温度和薄膜厚度的关系。分别通过紫外-可见光谱和Z-扫描的方法研究了Azo薄膜的线性光学性质以及薄膜的三阶非线性光学性质。结果表明:Azo薄膜的紫外-可见光谱比Azo溶液紫外可见光谱蓝移了61 nm, 该化合物薄膜的光学带隙 (Eg) 为2.71 eV; Azo薄膜呈现明显饱和吸收和自聚焦的非线性现象, 其三阶非线性极化系数达到10-7 (esu) 数量级, 这表明该类Azo化合物材料可以作为全光开关的候选材料。 相似文献
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采用脉冲激光沉积技术在熔石英基片上制备了c轴取向的锐钛矿相TiO2薄膜.通过X射线衍射和原子力显微镜对薄膜的结构、结晶性和表面特性进行了表征.通过透射光谱计算得到TiO2薄膜折射率约为2.1,光学带隙约为3.18eV.结合飞秒激光和Z扫描方法测量了薄膜的超快非线性光学特性,结果表明:锐钛矿TiO2薄膜具有负的非线性吸收系数和负的非线性折射率,其大小分别为-6.2×10-11m/W和-6.32×10-17m2/W,对应的三阶非线性极化率的实部和虚部分别为-7.1×10-11esu和-4.42×10-12esu.并计算薄膜的优值比T=βλ/n2≈0.8,表明锐钛矿相的TiO2在非线性光学器件方面具有潜在的应用前景. 相似文献
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通过真空熔融淬冷法制备了银复合的70GeS2-20In2S3-10CsI硫系玻璃样品, 利用Z-扫描技术研究了玻璃样品在800 nm处三阶非线性光学性质, 发现引入Ag可提高其折射率n和非线性折射率γ, n从2.204增加至2.4087, γ从23.3×10-18 m2/W增加到30.5×10-18 m2/W, 此外非线性响应时间从70 fs增加到79 fs。热处理对玻璃的非线性光学性能的影响研究显示, 热处理后样品的γ增加至44.3×10-18 m2/W, 是As2Se3玻璃的两倍多。发现析晶后带隙变小(吸收边红移)导致非线性吸收系数β减小, 使得样品的品质因子提高至3.3。Ag复合的硫系玻璃及玻璃陶瓷非线性折射率大、品质因子高、非线性响应快, 有望用于全关开关等各类非线性光学器件中。 相似文献
6.
采用射频磁控反应溅射法结合热退火处理技术制备纳米硅镶嵌氮化硅(nc-Si/SiNx)复合薄膜.通过X射线能谱(EDS)、红外光谱(IR)、X射线衍射(XRD)及紫外-可见吸收光谱(UV-vis)的测定,对薄膜进行了组分、键合状态、结构及光学带隙的表征.采用皮秒激光运用单光束Z扫描技术开展了对该复合薄膜的非线性光学性质的研究,测得其三阶非线性折射率系数和非线性光吸收系数分别为10-8esu和10-8m/W量级,并将薄膜这种三阶光学非线性增强的原因归因于量子限域效应. 相似文献
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采用喷雾热解法(SPD),分别使用甲醇、乙醇、异丙醇、正丁醇和去离子水作为溶剂制备F掺杂的SnO2(FTO)透明导电薄膜,使用X射线衍射仪、扫描电子显微镜、四点探针电阻仪、霍尔效应仪和紫外可见分光光度计等手段对薄膜进行测试和表征,研究了溶剂对FTO薄膜结构、形貌和光电性能的影响,研究了溶剂对FTO薄膜结构与光电性能的影响。结果表明:FTO薄膜具有四方相金红石结构;使用不同溶剂制备的薄膜,其表面形貌和颗粒尺寸明显不同;使用甲醇为溶剂制备的FTO薄膜呈现饱满的金字塔状,晶粒尺寸均匀,结构致密,具有最佳的综合光学和电学性能,其电阻率可达4.43×10-4 Ω·cm,载流子浓度为9.922×1020 cm-3,品质因数为1.646×10-2 Ω-1,可见光区透射比均大于75%。 相似文献
9.
为了提高聚吡咯(PPy)的光电性能,通过界面聚合-原位法制备了PPy/Cd S复合薄膜材料,用红外光谱、X射线衍射、扫描电镜、热重分析等方法对产物进行了表征。制备的PPy/Cd S薄膜结构平整,投料比对Cd S纳米棒尺度有明显影响。用紫外吸收、Z-扫描技术初步研究了PPy/Cd S的非线性光学(NLO)性质。PPy/Cd S具有明显的饱和吸收和非线性负折射。PPy/Cd S(摩尔比10∶1)薄膜的非线性折射率是PPy薄膜的2.4倍,三阶非线性极化率是PPy的2.1倍,说明PPy/Cd S薄膜具有良好的三阶NLO性能。该复合材料在光限幅等光电领域具有潜在的应用价值。 相似文献
10.
采用先驱体转化法在C/C复合材料基底表面制备了厚度为3~5μm的SiC薄膜和Si3N4薄膜;用球-盘对磨的方式测试了C/C复合材料基底、SiC薄膜和Si3N4薄膜在干态下的摩擦磨损性能。结果表明,制备的SiC薄膜和Si3N4薄膜表面结构均匀致密,无明显缺陷。C/C复合材料基底的平均摩擦系数为0.17,磨损率为1.93×10-4 mm3·N-1·m-1;SiC薄膜的平均摩擦系数为0.13,磨损率为0.78×10-4 mm3·N-1·m-1;Si3N4薄膜的平均摩擦系数为0.12,磨损率为0.45×10-4 mm3·N-1·m-1。与C/C复合材料基底相比,... 相似文献
11.
We report the fabrication and the nonlinear optical properties of Rh-doped BaTiO3 thin films. The films were deposited on SrTiO3 (100) substrates by pulsed-laser deposition. The deposited Rh:BaTiO3 thin films were single phase and c-axis orientation investigated by x-ray diffraction. The films exhibited large nonlinear optical effects, which were determined using Z-scan technique at a wavelength of 532 nm with a laser duration of 10 ns. The real and imaginary parts of the third-order nonlinear susceptibility chi (3) were 5.71 x 10(-7) esu and 9.59 x 10(-8) esu, respectively. The value of Re chi (3) of Rh:BaTiO3 films is much larger than those of several representative nonlinear optical thin films. The results show that Rh:BaTiO3 thin films have great potential applications for nonlinear optical devices. 相似文献
12.
We present the studies on third-order nonlinear optical properties of Al doped ZnO thin films irradiated with electron beam at different dose rate. Al doped ZnO thin films were deposited on a glass substrate by spray pyrolysis deposition technique. The thin films were irradiated using the 8 MeV electron beam from microtron ranging from 1 kG y to 5 kG y. Nonlinear optical studies were carried out by employing the single beam Z-scan technique to determine the sign and magnitude of absorptive and refractive nonlinearities of the irradiated thin films. Continuous wave He–Ne laser operating at 633 nm was used as source of excitation. The open aperture Z-scan measurements indicated the sample displays reverse saturable absorption (RSA) process. The negative sign of the nonlinear refractive index n2 was noted from the closed aperture Z-scan measurements indicates, the films exhibit self-defocusing property due to thermal nonlinearity. The third-order nonlinear optical susceptibility χ(3) varies from 8.17 × 10−5 esu to 1.39 × 10−3 esu with increase in electron beam irradiation. The present study reveals that the irradiation of electron beam leads to significant changes in the third-order optical nonlinearity. Al doped ZnO displays good optical power handling capability with optical clamping of about ∼5 mW. The irradiation study endorses that the Al doped ZnO under investigation is a promising candidate photonic device applications such as all-optical power limiting. 相似文献
13.
Wenjian Leng Chuanren Yang Hong Ji Jihua Zhang Jinlong Tang Hongwei Chen Lifeng Gao 《Journal of Materials Science: Materials in Electronics》2007,18(8):887-892
Linear and nonlinear optical properties of (Pb,La)(Zr,Ti)O3 (PLZT) ferroelectric thin films were presented in this paper. The PLZT ferroelectric thin films have been in situ grown on
quartz substrates by radio-frequency (RF) magnetron sputtering at 650 °C. Their crystalline structure and surface morphologies
were examined by X-ray diffraction and atomic force microscopy, respectively. It can be found that the PLZT thin films exhibit
well-crystallized perovskite structure and good surface morphology. The fundamental optical constants (the band gap energy,
linear refractive index, and linear absorption coefficient) were obtained through the optical transmittance measurements.
A Z-scan technique was used to investigate the optical nonlinearity of the PLZT thin films on quartz substrates. The films display
the strong third-order nonlinear optical effect. A large and negative nonlinear refractive index n
2 is determined to be 1.21 × 10−6 esu for the PLZT thin films. All results show that the PLZT ferroelectric thin films have potential applications in optical
limiting, switching, and modulated-type optical devices. 相似文献
14.
Fahimeh Abrinaei Marzieh Shirazi 《Journal of Materials Science: Materials in Electronics》2017,28(23):17541-17550
In the present study, it has been reported on the effect of Al doping on linear and nonlinear optical properties of ZnO thin films synthesized by spray pyrolysis method. The structural properties of ZnO thin films with different Al doping levels (0–4 wt%) were analyzed using X-ray diffraction (XRD). The results obtained from XRD analysis indicated that the grain size decreased as the Al doping value increased. The UV–Vis diffused refraction spectroscopy was used for calculation of band gap. The optical band gap of Al-doped ZnO (AZO) thin films is increased from 3.26 to 3.31 eV with increasing the Al content from 0 to 4 wt%. The measurements of nonlinear optical properties of AZO thin films have been performed using a nanosecond Nd:YAG pulse laser at 532 nm by the Z-scan technique. The undoped ZnO thin film exhibits reverse saturation absorption (RSA) whereas the AZO thin films exhibit saturation absorption (SA) that shows RSA to SA process with adding Al to ZnO structure under laser irradiation. On the other hand, all the films showed a self-defocusing phenomenon because the photons of laser stay on below the absorption edge of the ZnO and AZO films. The third-order nonlinear optical susceptibility, χ(3), of AZO thin films, was varied from of the order of 10?5–10?4 esu. The results suggest that AZO thin films may be promising candidates for nonlinear optical applications. 相似文献
15.
The inherent optical nonlinearities of thin silver films 总被引:1,自引:0,他引:1
Thin Ag films with the thickness of 80 Å were prepared by pulsed laser deposition technique. The films were grown on MgO(1 0 0) substrates under the nitrogen pressure of 5.0 Pa at room temperature. The surface images of the films were observed by atomic force microscopy. The linear optical properties of the films were studied in the wavelength range of 300–800 nm. The inherent third-order nonlinear optical responses coming from the silver material itself were determined by z-scan method at the wavelength of 532 nm with laser duration of 10 ns. The significant optical nonlinearities of the pure thin Ag films were determined to have the real and imaginary parts of the third-order nonlinear optical susceptibility (χ(3)) as 2.49 × 10−8 and 7.16 × 10−9 esu, respectively. The obtained χ(3) value of Ag films was about one order of magnitude larger than that of Ag colloids. 相似文献
16.
R. Murugesan S. Sivakumar P. Anandan M. Haris 《Journal of Materials Science: Materials in Electronics》2017,28(17):12432-12439
Pure, Barium and Nickel doped cadmium sulphide (CdS) thin films have been coated on glass substrates at 400?°C by spray pyrolysis technique. The prepared CdS and doped CdS thin films were analysed by various measurements such as X-ray diffraction (XRD), SEM, optical and Vibrating Sample Magnetometer (VSM). X-ray diffraction measurements show that the coated pure, Ba and Ni-doped CdS thin films belong to the cubic crystal structure with orientation preferentially along (111) direction. The average crystallite size of pure, Ba and Ni doped CdS thin films were determined as 31, 33 and 45 nm, respectively. The average dislocation density (δ) and stacking fault (SF) of pure, Ba and Ni doped CdS thin films were also determined. The surface morphology and elemental analysis of the thin films were determined by scanning electron microscopy and energy dispersive X-ray spectrum (SEM with EDAX). It is observed that the optical energy bandgap has been decreased from 2.43 to 2.1 eV due to the doping Ba. The luminescence spectrum shows a strong emission peak at 517 nm in the case of pure CdS thin film and a meager red shift has been observed due to the doping. VSM studies were employed to study the magnetic behaviour of Ba and Ni doped CdS thin films. 相似文献
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The optical absorption coefficients of highly oriented laser-evaporated thin films were determined from the measured reflectance R(λ) and transmittance T(λ) in the wavelength range 400–1700 nm. The optical absorption spectrum of CuInSe2 thin films shows three energy gaps, which are associated with the fundamental edge and valence band splitting by the tetragonal crystal-field and spin-orbit effects, and four optical transitions from the copper d levels to the conduction bands. 相似文献
19.
The optical properties of vapour chopped and nonchopped undoped tin oxide thin films (1000 Å) have been studied. The films were prepared by thermal oxidation (in air) of vacuum evaporated vapour chopped and nonchopped tin thin films. Effect of varied oxidation temperature and duration was also studied. As revealed by X ray diffraction studies, polycrystalline (both tetragonal and orthorhombic) films were obtained. The refractive indices ranged from 1.575 to 1.667 and 1.600 to 1.810 for nonchopped and vapour chopped tin oxide films respectively. Refractive index was found to increase after ageing. The effect was found lower in vapour chopped films. The direct band gap values ranged from 2.18 to 2.51 and 2.95 to 3.08 for nonchopped and vapour chopped tin oxide films respectively. The films showed high optical transmittance in the visible range of the spectrum. It was observed that the heat treatment process strongly affects the properties of the films. The vapour chopped tin oxide thin films showed higher packing density, optical band gap and refractive index with lower ageing effect. 相似文献