V2O5薄膜的结构和光电性能研究

在O2／Ar混合气氛中，用脉冲磁控溅射金属V靶沉积出非晶的V2O5薄膜。对所沉积的薄膜进行450℃退火。利用X射线衍射、原子力显微镜、分光光度计和电阻测量等手段对薄膜的结构和性能进行了分析，从200nm-2500nm光谱的透射和反射测量结果，计算出薄膜的吸收系数。结果表明，V2O5薄膜纯度高，结晶好，高低温电阻变化2个量级。光学能隙为2．46eV。     

V2O5薄膜的结构和光电性能研究

在O2 /Ar混合气氛中 ,用脉冲磁控溅射金属V靶沉积出非晶的V2 O5薄膜。对所沉积的薄膜进行 4 5 0℃退火。利用X射线衍射、原子力显微镜、分光光度计和电阻测量等手段对薄膜的结构和性能进行了分析 ,从 2 0 0nm～ 2 5 0 0nm光谱的透射和反射测量结果 ,计算出薄膜的吸收系数。结果表明 ,V2 O5薄膜纯度高 ,结晶好 ,高低温电阻变化 2个量级。光学能隙为2 4 6eV。     

热处理对V2O5-TiO2复合薄膜表面结构与光学性能的影响

以钛酸丁脂、V2O5粉末为前驱体,采用溶胶-凝胶法制备了V2O5-TiO2复合薄膜,并采用X射线光电子能谱(XPS)和Uv-vis-nir分光光度计等方法研究了热处理对薄膜性能的影响.结果表明,随热处理温度的升高,复合薄膜中钛离子的价态不变,仍为Ti4 ;而V4 离子逐渐被氧化为V5 离子;并采用氢氧基团、碳氧键与多种钒离子进行叠加拟合,拟合结果与实验曲线非常符合;V2O5-TiO2复合薄膜在紫外光波段的透射率减小,吸收带边出现红移.     

V2O5－x薄膜电极材料的氟化及性能研究

用脉冲激光沉积法制备了V2O5-x氧化物薄膜电极材料，用XeF2对其进行了氟化改性，并对比了电极材料氟化前后的充放电性能的变化。实验结果表明：氟化后的V2O5-x薄膜氟化后循环性能明显得到改善，经过200次循环充放电依然保持较高的充放电容量。     

V2O5干凝胶薄膜的制备及应用

综述了V2O5干凝胶（VXG）薄膜的结构组成特性，介绍了VXG薄膜的制备方法及其在电压开关、气体传感器、湿度传感器、智能窗和锂电池等领域的应用，指出了该研究存在的问题和发展前景。     

非晶氧化钒薄膜光学性质研究

在氩氧混合气氛中,常温下用脉冲磁控溅射方法在石英玻璃和硅片上制备了V2O5薄膜。用X射线衍射、X射线光电子谱和原子力显微镜对薄膜微观结构进行了测试,用分光光度计测量从200～2500nm波段V2O5薄膜的透射和反射光谱。结果表明,常温下制备的V2O5薄膜为非晶结构,光学能隙为2.46eV。     

V2O5薄膜在传感器上的研究进展

V2O5薄膜具有优异的物理、化学性质,在化工催化、电子、电化学等许多领域有广泛的应用,由于V2O5薄膜对还原性气体和湿度具有良好的敏感特性,其在气体和湿度传感器上的研究也日渐广泛,因此本文综述了V2O5为基体的薄膜在气体传感器和湿度传感器上的研究进展及存在的问题和解决的思路.     

Ta2O5薄膜的结构和电学性能研究

采用紫外光诱导热丝CVD沉积技术制备Ta2O5薄膜和Al/Ta2O2/SiMOS电容。利用XRD，AFM测试分析方法研究了紫外光源功率对Ta2O5薄膜结构的影响；通过C-V和，I-V测试对Ta2O5薄膜的介电常数，击穿场强和漏电流等电学性能进行了研究，结果表明：紫外光源的功率越大，Ta2O5薄膜的结晶性越好，介电常数越大，最大值为29，但紫外光功率对击穿场强和漏电流没有明显改善。     

二氧化钒薄膜微结构和光学相变特性

二氧化钒薄膜是最有前途应用到非制冷红外微测热辐射计的材料，它的特性与制备方法、化学计量比、结构和取向等有直接关系，仔细控制工艺参数是制备应用的VO2薄膜关键。研究中采用脉冲磁控反应溅射方法，通过精确地控制功率、氧分压、基底温度等关键工艺参数，在石英玻璃和硅片上制备VO2薄膜。利用X射线衍射和x射线光电子谱，分析了薄膜的成分、相结构、结晶和价态情况，用原子力显微镜表征了薄膜的微观结构，在光谱仪对VO2薄膜的高低温光学特性原位测量。结果表明，得到的VO2薄膜纯度高、相结构单一、结晶度、多晶生长。在波数2000cm^-1高低温透射变化达到51％。     

Li2O-V2O5-SiO2薄膜结构与电化学性能研究

采用355nm脉冲激光沉积(PLD)法以Li6.16V0.61Si0.39O5.36为靶制备了Li2O-V2O5-SiO2薄膜.由X射线衍射(XRD)、扫描电子显微镜(SEM)、表面轮廓、交流阻抗(ACI)、直流极化(DCP)等方法对薄膜的形貌、结构及电化学性能进行表征,讨论了Li2O-V2O5-SiO2薄膜电化学性能与其结构的关系.结果表明,该薄膜是一种无针孔和裂缝、厚度均匀、组成致密的非晶态结构;Li2O-V2O5-SiO2薄膜离子电导率与温度符合Arrhenius关系,离子迁移数接近1.0(tion＞99.999%),是一种性能良好的离子导体材料;Li2O-V2O5-SiO2薄膜室温时离子电导率达4.0×10-7S/cm,而电子电导率仅为10-11～10-12S/cm,可作为电解质材料用于全固态薄膜锂电池.     

Electrical and optical properties of thin films of hydrated vanadium pentoxide featuring electrochromic effect

Thin films of hydrated vanadium pentoxide (V₂O₅ · nH₂O) exhibit the phenomenon of electrochromism, whereby a film reversibly changes its color under the action of an applied electric field. A specific feature of this phenomenon is that it takes place in a “dry” planar system, in the absence of an electrolyte, which makes this system promising for various applications. We have studied changes in the optical and electrical properties of hydrated vanadium pentoxide films under the conditions of electrochromic coloration.     

Structural and electrochromic properties of molybdenum doped vanadium pentoxide thin films by sol-gel and hydrothermal synthesis

Molybdenum-doped vanadium pentoxide (Mo-doped V₂O₅) thin films with doping levels of 3-10 mol% were prepared by dip-coating technique from a stable Mo-doped V₂O₅ sol synthesized by sol-gel and hydrothermal reaction. The Mo-doped V₂O₅ films had a layered V₂O₅ matrix structure along c-axis orientation with Mo⁶⁺ as substitutes. Values of the inserted and extracted charge density of 21.4 and 21.3 mC·cm^− 2 and the transmittance variation (ΔT at 640 nm) between anodic (+ 1.0 V) and cathodic (− 1.0 V) colored states of 41% were observed for the films with 5 mol% Mo⁶⁺ doping. Above this dopant concentration, the charge capacity and ΔT decreased. The enhancement of the electrochemical and electrochromic properties of the films is related to changes in the electronic properties of V₂O₅ films due to the creation of energy levels in the band gap of V₂O₅ by the Mo doping, accompanied by the reduction of the forbidden-band width and the increase of the conductivity.     

Optical properties of vanadium thin films

The optical constants of vanadium thin films of different thicknesses were determined in the spectral range of 2.5 to 8.5 m. These optical constants were used to evaluate some microcharacteristics of vanadium thin films such as the free charge concentration, the relaxation time, the static conductivity, the electron velocity at the Fermi surface, the mean free path and the specularity parameter.The determination of the microcharacteristics were carried out in conjunction with Drude's theory of free charge carriers as well as with anomalous skin effect theory.     

Dynamic optical limiting experiments on vanadium dioxide and vanadium pentoxide thin films irradiated by a laser beam

Vanadium dioxide (VO2) and vanadium pentoxide (V2O5) thin films are irradiated by a near-infrared continuous-wave laser beam and the dynamic optical limiting performance is measured. The temperature varying with time of the films induced by a laser beam is also recorded by an IR thermal sensor. Under the irradiation of a laser beam with an intensity of 255 W/cm2 and a spot diameter of 2 mm, the laser beam transmittance of the VO2 film decreases from 47% before phase transition to 28% after phase transition, and the response time is approximately 200 ms; the laser beam transmittance of the V2O5 film decreases from 51% before phase transition to 24% after phase transition, and the response time is approximately 40 ms. The optical limiting is realized by this laser heating-induced phase transition.     

Structural and optical properties of vanadium pentoxide sol–gel films

The V₂O₅ films were obtained using sol–gel procedure. The composition and mesostructure of the layers were investigated with the UV and Raman spectroscopy, as well as with electron microscopy. We showed that the changes in the properties of thin layers accompanying the variation of film thickness are connected with the changes in the microstructure of the film rather than with changes in its composition. The thin V₂O₅ layers obtained in the present study are composed of disordered clusters; their mean size is 4–13 nm.     

Microstructural properties of electrochemically synthesized ZnSe thin films

In this study, we report the electrosynthesis of zinc selenide (ZnSe) thin films on indium-doped tin oxide-coated glass substrates. The deposited ZnSe thin films have been characterized for structural (X-ray diffraction), surface morphological (scanning electron microscopy), compositional (energy dispersive analysis by X-rays), photo luminescence property, and optical absorption analysis. Formation of cubic structure with preferential orientation along the (111) plane was confirmed from structural analysis. In addition, the influence of the deposition potential on the microstructural properties of ZnSe is plausibly explained. The optical properties of ZnSe thin films are estimated using the transmission spectrum in the range of 400–1200 nm. The optical band gap energy of ZnSe thin films was found to be in the range between 2.52 and 2.61 eV. Photoluminescence spectra were observed at blue shifted band edge peak. The morphological studies depict that the spherical and cuboid shaped grains are distributed evenly over the entire surface of the film. The sizes of the grains are found to be in the range between 150 and 200 nm. The ZnSe thin film stoichiometric composition was observed at optimized deposition condition.     

Electrical properties of vanadium tungsten oxide thin films

The vanadium tungsten oxide thin films deposited on Pt/Ti/SiO₂/Si substrates by RF sputtering exhibited good TCR and dielectric properties. The dependence of crystallization and electrical properties are related to the grain size of V_1.85W_0.15O₅ thin films with different annealing temperatures. It was found that the dielectric properties and TCR properties of V_1.85W_0.15O₅ thin films were strongly dependent upon the annealing temperature. The dielectric constants of the V_1.85W_0.15O₅ thin films annealed at 400 °C were 44, with a dielectric loss of 0.83%. The TCR values of the V_1.85W_0.15O₅ thin films annealed at 400 °C were about −3.45%/K.     

磁控溅射制备五氧化二钒薄膜的研究

采用射频磁控溅射的方法,在不同条件下制备了氧化钒薄膜样品,分别在不同温度条件下做了退火处理,并对退火前后样品做了X射线衍射(XRD)、X射线光电子能谱(XPS)和激光扫描共聚焦显微镜测试与分析,旨在得出制备良好的V2O5 薄膜的条件。     

Optical properties of thin films of amorphous vanadium oxides

The results of an experimental investigation of the optical properties of anodic vanadium oxide films are presented. It is shown that films of different phase composition (VO₂, V₂O₅, or a mixture of two phases) can be obtained, depending on the oxidation regime, and that the absorption and transmission spectra are modified significantly in accordance. The optical properties of the oxides, whose composition is close to stoichiometric vanadium dioxide, demonstrate the occurrence of a metal-semiconductor phase transition in the amorphous films. The results presented are important both from the standpoint of technical applications of thin film systems based on anodic vanadium oxides and for more detailed understanding of the physical mechanism of the metal-semiconductor phase transition and the influence of structural disorder on the transition. Pis’ma Zh. Tekh. Fiz. 25, 81–87 (April 26, 1999)