氩氧比与退火温度对磁控溅射VO2薄膜结构与电学性能的影响

采用反应直流磁控溅射法,通过调控溅射过程中的氩氧比,在石英玻璃衬底上制备了氧化钒薄膜,研究了溅射气氛及后处理条件对其微结构与电学性能的影响.经450和500℃退火,薄膜中易形成VO2,而550℃退火时薄膜中会形成大量非4价的钒氧化物.薄膜在较高温度500℃下退火时结晶度增加,但薄膜颗粒之间的间隙更为明显,导致电阻率显著提高;同时其电阻率-温度曲线的热滞回线宽度较窄,在加热过程中相转变温度较高.当氩氧比中氧含量增加时,沉积的VO2薄膜中生成了少量非4价的钒氧化物.结果表明,反应磁控溅射法制备的氧化钒薄膜的微结构、电阻率、相变温度等特性与氩氧比和后退火温度密切相关.     

Pd掺杂SnO2气敏薄膜XPS分析及其气敏性能研究

分别在氧气和氩气气氛下,于纯SnO<,2>气敏薄膜上溅射金属Pd制备了Pd掺杂SnO<,2>,气敏薄膜.利用XPS分析了溅射气氛和老化处理对该气敏薄膜表面元素含量变化的影响.结果表明:溅射气氛和老化处理对气敏薄膜的表面吸附氧含量和其他元素的含量均有很大影响,如氩气气氛下制备的Pd/SnO<,2>气敏薄膜在老化前与400...     

在二氧化硅衬底上制备磁光Ce：YIG薄膜用于磁光波导型器件

对Ce1YIG磁光薄膜的制备过程及磁光性能进行了详细的研究．用RF磁控溅射法在二氧化硅的基片．上淀积Ce1YIG薄膜,再对此薄膜进行晶化处理,以得到具有磁光性能的Ce1YIG薄膜．本文讨论了晶化过程中,Ce1YIG薄膜微观结构的变化对其磁光性能的影响．结果表明：采用波长为630nm的可见光测量,薄膜的饱和法拉第旋转系数θF为0．8deg／μm．同时,晶化薄膜易磁化方向为平行于膜面方向,其居里温度点为220℃．所得Ge1YIG薄膜的参数表明：所制备的薄膜适宜于制备波导型磁光隔离器．     

溶胶—凝胶沉积PbTiO3薄膜成分和结构的XPS分析

对通过Ｓｏｌ－ｇｅｌ工艺制备的ＰｂＴｉＯ３薄膜在Ａｒ＾＋溅射前后作了ＸＰＳ全扫描和窄扫描测量，结果表明，除了薄膜原始表面有化学吸附氧和污染碳外，薄膜中没有残余的单质碳或其他杂质元素存在，薄膜的元素组成与化学计量比一致，薄膜表面无富集Ｐｂ。各元素的化学状态证实薄膜系ＰｂＴｉＯ３钙钛矿型结构，Ａｒ＾＋溅射引起Ｐｂ择优溅射和化合物分解，以致Ａｒ＾＋溅射后薄膜表面元素组成与化学状态严重偏离薄膜体内层的真实     

磁控溅射法制备LiTaO3薄膜及其结晶性能研究

用射频磁控溅射法在Pt/Ti/SiO₂/Si(100)基片上沉积了LiTaO₃薄膜,并在氧气气氛中不同温度下进行退火。采用SEM、XRD、XPS等表征方法分析了薄膜的结晶性能、各元素化学价态和元素原子百分比。结果表明,经700℃退火处理1h得到的薄膜结晶性能最好,在(104)晶向上具有强烈的择优取向性。薄膜退火温度的升高导致薄膜中Li空位缺陷和O空位缺陷减少。研究表明,薄膜中O/Li的原子比对结晶性能有着非常明显的影响,原子值越接近晶体化学计量比,结晶性能越好。     

Bi_(1.5)Mg_(1.0)Nb_(1.5)O_7薄膜的介电损耗机理研究

采用射频磁控溅射法在Al2O3基片上沉积了铌酸铋镁(Bi1.5Mg1.0Nb1.5O7,BMN)薄膜,研究了不同退火条件下BMN薄膜的介电损耗机理。结果表明,充分的退火能够减小氧空位缺陷密度,并降低介电损耗。氧气气氛下退火能够有效补偿BMN薄膜中的氧空位,使得介电损耗进一步降低。这说明氧空位导致的带电缺陷损耗是BMN薄膜材料主要的介电损耗机制。此外,BMN薄膜中也存在晶界损耗机制。     

直流反应溅射三氧化二铝膜的制备和硅上溅射膜的研究

本文介绍了将直流反应溅射技术应用于制备三化二铝薄膜的实验情况,给出了硅衬底溅射三氧化二铝膜的实验结果.除了研究影响溅射的因素以确定适当的溅射条件外,本文着重讨论了如何控制膜内的电荷极性.找到影响电荷极性的主要因素是溅射过程中基片所处的位置.测出了在一定溅射条件下,电荷极性、电荷密度随基片与阴极间距的变化关系.实验说明在两个平板电极间辉光放电的不同区域中会形成正的或负的氧离子,这些氧离子被置于不同区域中的基片所吸附而形成了淀积膜内的正电荷或负电荷.     

掺铒a-Si:H,O薄膜1.54μm光致发光和微结构

采用等离子化学气相淀积方法,改变SiH4和N2O的流量比制备含有不同氧浓度的a-Si：H,O薄膜.用离子注入方法掺入铒,经300一935℃快速热退火,在波长1.54μm处观察到很强的室温光致发光.氧的加入可以大大提高铒离子的发光强度,并且发光强度随氧含量的变化有一个类似于高斯曲线的分布关系,不是单调地随氧含量的增加而增强.研究了掺铒a-Si:H,O薄膜和微结构,讨论了发光强度与薄膜微结构的关系.     

掺铜TiO2薄膜的制备及结构与光学性能的研究

采用双靶直流磁控共溅射法制备了掺铜TiO2薄膜,通过控制Cu靶的溅射功率改变Cu的掺杂量,研究了掺铜对TiO2薄膜的结构、光吸收及光催化性能的影响.结果表明:掺Cu能够改善薄膜的表面形貌与结晶质量,提高薄膜的光吸收性能.随着掺铜量的增加,TiO2薄膜的锐钛矿(101)衍射峰越来越强,且吸收边逐渐红移.Cu靶的溅射功率大于3 W,薄膜中就会出现CuO晶相.掺Cu后,TiO2薄膜的光催化性能明显增强.随着Cu的溅射功率的增大,TiO2薄膜的光催化性能先增强,后减弱.Cu的溅射功率为5 W的样品光催化性能最好.     

用XPS法研究硅基硫化锌薄膜

应用X射线光电子能谱(XPS)研究Si基ZnS:Cu,Er薄膜的化学元素组成、分布和价态,认为Cu元素只有少数部分进入晶格中替代Zn2 起激活剂的作用,Er元素在ZnS基质中分布不均匀,且会与氧结合.PL测试发现样品发绿光,主要发光峰出现劈裂,对研究薄膜中的杂质中心、实现Si基发光有参考意义.     

Stable resistive switching characteristics of Ce:HfOx film induced by annealing process

In this work, Ce:HfO_x films were fabricated and the resistive switching characteristics were investigated. The chemical bonding states of the films were explored by X-ray photoelectron spectroscopy. The annealing process was carried out to modulate the concentration of oxygen vacancies in the film to confirm the dominant role of oxygen vacancies on resistive switching behaviors, which resulted in the elimination of unstable oxygen vacancies and the introduction of oxygen vacancy near Ce dopants due to the reduction of Ce⁴⁺. Benefiting from the oxygen vacancies near Ce dopants, stable resistive switching performance can be achieved for the annealed Ce:HfO_x sample. A schematic diagram based on the formation and rupture of oxygen vacancy filaments was proposed to illustrate the switching behaviors of annealed Ce:HfO_x sample.     

Novel Bi-substituted Yttrium Iron Garnet Film／Crystal Composite for Magneto-optical Applications

The novel Bi-substituted rare-earth iron garnet films were grown by the modified liquid phase epitaxy (LPE) technique for use as a 45° Faraday rotator in optical isolators. First, single crystals of Y3 Fe5 O12(YIG), with a lattice constant of 1. 237 8 nm, were grown by means of the Czochralski method. Using the seed crystal of YIG instead of the conventional non-magnetic garnet of Gd3Ga5O12 (GGG) as a substrate,a film of BiYbIG was grown by means of the LPE method from Bi2O3 - B2O3 fluxes. The structural, magnetic and magneto-optical properties of BiYbIG LPE film/YIG crystal composite have been investigated using directional X-ray diffraction (XRD), electron probe microanalysis (EPMA), vibrating sample magnetometer (VMS) and near-infrared transmission spectrometry. The saturation magnetization 4πMs has been estimated to be about 1.2×10 6 A/m. The Faraday rotation spectrum was measured by the method of rotating analyzer ellipsometry (RAE) with the wavelength varied from 800 nm to 1 700 nm. The resultant Bi0.37 Yb2.63 Fe5 O12LPE film/YIG crystal composite showed an increased Faraday rotation coefficient due to doping Bi3 ions into the dodecahedral sites of the magnetic garnet without increasing absorption loss, therefore a good magnetooptic figure of merit,defined by the ratio of Faraday rotation and optical absorption loss, has been achieved of 21.5 and 30.2 (°)/dB at 1 300 and 1 550 nm wavelengths respectively and room temperature. Since Yb3 and Y3 ions provide the opposite contribution to the wideband and temperature characteristics of Faraday rotation,the values of Faraday rotation wavelength and temperature coefficients were reduced to 0.06 %/nm and 0.007(°)/℃ at 1 550 nm wavelength, respectively.     

Optical Faraday rotator using Ce-substituted fibrous YIG singlecrystal grown by floating-zone method with YAG laser heating

A new optical Faraday rotator using a fibrous Ce-substituted yttrium-iron-garnet (Ce:YIG) single crystal was developed. The fibrous Ce:YIG single crystal was successfully grown by the floating-zone method with infrared-assisted YAG laser heating at a fast growth rate. This crystal has a good quality and shows a better figure-of-merit for an optical Faraday rotator at wavelength λ=1.55 μm compared with commonly used Bi-substituted YIG films. Ce:YIG single crystals grown by our method are expected to reduce the cost of optical isolators     

离子束溅射宽带吸收薄膜设计与制备技术研究

Si薄膜在可见光和近红外波段具有一定的吸收特性,可用于宽带吸收薄膜的制备。采用离子束溅射技术,在熔融石英基底上制备了不同沉积工艺参数的Si薄膜,基于透、反射光谱和椭偏光谱的全光谱数值拟合法,计算了Si薄膜的光学常数,并研究了氧气、氮气流量对其光学特性的影响。选择Si和Ta2O5作为高折射率材料、SiO2作为低折射率,设计了吸收率为2%和10%的宽带（1 000~1 400 nm）吸收薄膜。采用离子束溅射沉积技术,在熔融石英基底上制备了宽带吸收薄膜,对于A=2%的宽带吸收光谱,在1 064、1 200、1 319 nm的吸收率分别为2.12%、2.15%和2.22%;对于A=10%的宽带吸收光谱,在1 064、1 200、1 319 nm的吸收率分别为9.71%、8.35%和9.07%。研究结果对于吸收测量仪、光谱测试仪等仪器的定标具有重要的作用。     

FeS_2薄膜厚度对晶体生长及光吸收特性的作用

在单晶Si衬底上用磁控溅射Fe膜并硫化的方法 ,制备了不同厚度的FeS2 薄膜 ,测定了晶体结构及光学性能 .结果表明 ,薄膜晶体学位向分布随薄膜厚度的增大可发生一定程度的变化 .随着薄膜厚度增加到 330nm ,晶粒尺寸增加而晶格常数减小 ;但当薄膜厚度大于 330nm时 ,晶粒尺寸下降而晶格常数增大 .光吸收系数以及禁带宽度均随薄膜厚度的增加而下降 .相变应力、比表面积及晶体缺陷随薄膜厚度的变化是引起薄膜晶体生长行为及光吸收性能变化的主要原因     

Electrical and optical properties of zinc-oxide films deposited by the ion-beam sputtering of an oxide target

The influence of the parameters of the deposition process on the stoichiometric composition and electrical and optical properties of ZnO films deposited by the ion-beam sputtering of a ZnO target is studied. It is established that, upon sputtering of a ZnO target with stoichiometric composition, there is a deficit of oxygen in the films deposited. Even for the case of target sputtering in a pure O₂ atmosphere, the stoichiometry index of the films is no higher than 0.98. A decrease in the oxygen content in the films is accompanied by a sharp decrease in the resistivity to 35–40 Ω m, narrowing of the optical band gap, and a shift of the optical transmittance edge from 389 to 404 nm. All of the variations in the optical and electrical properties of the ZnO films can be attributed to variations in the concentration and mobility of free charge carriers in the films.     

CIGS Thin Films for Cd-Free Solar Cells by One-Step Sputtering Process

Cu(In_1?x Ga _x )Se₂ (CIGS) thin films were deposited by a one-step radio frequency (RF) magnetron sputtering process using a quaternary CIGS target. The influence of substrate temperature on the composition, structure, and optical properties of the CIGS films was investigated. All the CIGS films exhibited the chalcopyrite structure with a preferential orientation along the (112) direction. The CIGS film deposited at 623 K showed significant improvement in film crystallinity and surface morphology compared to films deposited at 523 and 573 K. To simplify the manufacturing procedure of solar cells and avoid the use of the toxic element Cd, the properties of ZnS films prepared by RF sputtering were also investigated. The results revealed that the sputtered ZnS film exhibits good lattice matching with the sputtered CIGS film with significantly lower optical absorption loss. Finally, all-sputtered Cd-free CIGS-based heterojunction solar cells with the structure SLG/Mo/CIGS/ZnS/AZO/Al grids were fabricated without post-selenization. Furthermore, the results demonstrated the feasibility of using a full sputtering process for the fabrication of Cd-free CIGS-based solar cell.     

工艺条件对柔性衬底ITO薄膜光电性能的影响

采用直流磁控溅射法在柔性衬底上镀制ITO透明导电薄膜,全面研究了薄膜厚度、氧气流量、溅射速率、溅射气压和镀膜温度等工艺条件对ITO薄膜光电性能的影响。结果表明,当膜厚大于80nm、氧氩体积比为1∶40、溅射速率为5nm/min、溅射气压在0.5Pa左右、镀膜温度为80～160℃时,ITO薄膜的光电性能较好,其电阻率小于5×10–4?·cm、可见光透光率大于80%。     

Flat-top response in one-dimensional magnetic photonic bandgapstructures with Faraday rotation enhancement

The transmission and Faraday rotation characteristics of one-dimensional photonic crystals in cerium-substituted yttrium iron garnet (Ce:YIG) with multiple defects in the optical bandgap are studied theoretically at λ = 1.55 μm. It is found that the interdefect spacing can be adjusted to yield a flat top response, with close to 100% transmission and 45° Faraday rotation, for film structures as thin as 30 to 35 μm. This is better than a three-fold reduction in thickness compared to the best Ce:YIG films for comparable rotations, and may allow a considerable reduction in size in manufactured optical isolators. Transmission bands as wide as 7 nm are predicted, which constitutes a considerable improvement over previously reported bandwidths for magnetic photonic crystals. Diffraction across the structure corresponds to a longer optical path length than the thickness of the film, calling for the use of guided optics to minimize insertion losses in integrated devices. The basis for the flat-top transmission in ferrite photonic crystals is presented and discussed