MgO二次电子发射功能薄膜的制备方法

综述了具有二次电子发射功能的MgO薄膜的主要制备方法,包括电子束蒸发、磁控溅射、溶胶一凝胶、分子柬外延和脉冲激光沉积法。阐述了各种方法在制备MgO薄膜方面的优点和不足,讨论了不同的制备方法对MgO薄膜结晶取向、表面形貌等性质的影响。分析表明,利用磁控溅射法制备MgO薄膜可获得较高的二次电子发射率。     

沉积气压对电弧离子镀制备MgO薄膜的结构及性能的影响

采用阴极真空电弧离子沉积技术在玻璃及Si衬底上成功地制备了具有择优结晶取向的透明MgO薄膜。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）及紫外-可见吸收光谱仪分别对MgO薄膜微观结构、表面形貌及可见光透过率进行了测试与分析。XRD结果表明,所制备的MgO薄膜具有NaCl型立方结构的（100）、（110）和（111）3种结晶取向,在沉积气压为0.7～3.0Pa的范围内,薄膜的择优结晶取向随沉积气压的升高先由（100）转变为（110）,最后变为（111）。SEM图表明随着沉积气压的升高,MgO薄膜的晶粒逐渐变小,薄膜结晶质量变差。在380～900nm范围内,沉积气压为0.7Pa下制备的MgO薄膜其可见光透过率高于90%,随着沉积气压的升高,薄膜的可见光透过率有所下降。     

超声喷雾热解法制备MgO薄膜及性能研究

采用自制超声喷雾热解装置制得MgO薄膜,用X射线衍射、扫描电子显微镜、紫外可见光分光光度计等研究了MgO薄膜的晶体及微观结构。结果表明,随着沉积温度的提高,薄膜的结晶性能变好,光透射率随之升高;当沉积温度为650℃时,薄膜的晶粒为52.295nm,在可见光波段透射率达到77%。沉积温度对MgO薄膜的晶体结构、表面形貌以及光学特性有显著影响,是调控MgO薄膜结构和光学特性的有效手段。     

碳化硼薄膜制备的研究进展

综述了碳化硼材料的主要性能和制备碳化硼薄膜的主要方法,讨论了包括磁控溅射、离子束沉积和化学气相沉积等制备方法的优点及重要工艺参数,并就各方法指出了提高薄膜性能的主要措施,指出制备出更均匀、致密的碳化硼薄膜,提高薄膜与基体间的结合力,降低薄膜应力仍是今后研究的重点.     

镍铬合金薄膜的研究进展

镍铬合金薄膜是重要的精密电阻和应变电阻薄膜材料.简述了镍铬合金薄膜的3种制备方法:真空蒸发沉积、磁控溅射沉积和离子束沉积;讨论了基底、工作气压、沉积时间等薄膜制备工艺参数以及退火工艺对薄膜性能的影响.重点叙述了镍铬合金薄膜、改良型镍铬合金膜、含氮镍铬合金膜、镍铬合金多层膜和纳米镍铬合金薄膜等膜系的特征.阐明了制备具有高电阻率、低电阻温度系数、高应变灵敏系数、良好的热稳定性等优异综合性能的镍铬合金薄膜的新工艺发展趋势.     

染料敏化太阳能电池MO／TiO2复合薄膜的制备与表征

用溶胶-凝胶法结合旋转镀膜法制备致密TiO2薄膜，采用丝网印刷技术制备多孔TiO2薄膜，采用液相沉积法制备ZnO／Ti02、MgO／TiO2复合薄膜。用x射线能谱仪、原子力显微镜、紫外-可见分光光度计对复合薄膜的化学组分、表面形貌、吸光性能等进行分析；组装电池，测定了电池性能。结果表明：ZnO／TiO2、MgO／TiO2复合薄膜具有较好的光电性能，染料敏化太阳能电池的短路电流、开路电压、填充因子、光电转换效率均得到提高。     

外延SCNN电光薄膜生长及研究

用激光脉冲沉积(PLD)法在MgO(001)衬底上成功地生长、制备出了外延铌酸锶钡钠(SCNN)电光薄膜.对生长制备出的SCNN电光薄膜用X射线衍射对其微观结构进行了测量研究;X射线衍射结果显示生长在MgO(001)衬底上的SCNN电光薄膜是外延膜;对生长在MgO(001)衬底上的外延SCNN电光薄膜在200～900nm光谱范围的透射光谱进行了测量研究,通过对薄膜透射光谱的振荡曲线分析计算得到了SCNN电光薄膜的光学常数,结果发现外延SCNN电光薄膜的折射率符合单电子模型.     

SiC薄膜制备工艺进展

本文综述了ＳｉＣ薄膜的制备工艺及进展，介绍了物理气相沉积、化学气相沉积、等离子化学气相沉积及光化学气相沉积等各种ＳｉＣ薄膜的制备方法，简单阐述了各种工艺对薄膜性能的影响，评述了各种制备工艺的优缺点。     

柔性高阻隔薄膜材料的研究现状

目的为柔性高阻隔薄膜的应用提供理论指导。方法综述柔性高阻隔膜的应用现状及存在问题,总结热蒸发、化学气相沉积、原子层沉积等制备柔性高阻隔薄膜的方法、原理、特点及应用,展望高阻隔膜包装材料的发展前景。结果高阻隔薄膜制备工艺趋向于单次制备,采用等离子体辅助原子层沉积技术是制备超高阻隔薄膜的首选,原子层沉积(ALD)和分子层沉积(MLD)结合也是获得超高阻隔薄膜的未来发展方向。结论快速、高效地制备柔性高阻隔薄膜是包装工业的发展趋势。     

氧化物异质外延薄膜生长的计算机模拟

利用Monte Carlo方法分别模拟了在SrTiO3基底上沉积MgO薄膜和在MgO基底上沉积SrTiO3薄膜.模拟中,选取与实验中薄膜生长相近的参数条件,引入了新的参数扩散势垒,得到了在晶格正失配(张应力)和负失配(压应力)下薄膜生长的形貌图以及薄膜粗糙度的变化曲线图,分析了张应力和压应力对薄膜生长形貌的影响.模拟结果与文献报道的外延薄膜生长模式的实验观察结果一致.     

离子轰击MgO薄膜二次电子发射的研究

氧化镁因其二次电子发射系数高、抗溅射能力强等优异的性能,广泛应用于平板显示器等电子器件中,其二次电子发射性能有重要的研究价值。介绍了离子轰击下氧化镁薄膜发射的二次电子的典型测量装置及相关研究结论,总结了离子轰击下氧化镁薄膜二次电子的发射特性,同时对离子轰击的材料产生的二次电子发射的研究提出了建议。脉冲中和法比较适用于离子轰击下的氧化镁薄膜的二次电子发射的测量;不同晶面的MgO薄膜的二次电子发射系数不同,（111）晶面最高;低能离子入射情况下,二次电子的能量分布与离子类型无关。     

The effect of Fe-doped magnesium oxide thin film in alternative current plasma display panel

In order to improve the discharge characteristics of MgO thin film as a protective layer in an alternative current plasma display panel, Fe-doped MgO thin films was introduced. Both the surface characteristics of the deposited thin films and the electro-optical properties of 4 inch test panels were investigated. It has been demonstrated experimentally that ac PDP with Fe-doped MgO protective layer has lower discharge voltage than that of undoped MgO film, which corresponds to measured secondary electron emission coefficients. The crystallinity and surface roughness of thin films were determined by XRD patterns and AFM images.     

Effects of self-erasing discharge on panel-aging characteristics in AC plasma display panel

This paper investigates the changes in the surface morphology of the MgO thin film on the ITO and bus electrodes in ac plasma display panel under various sustain voltages during the panel-aging process. It is found that the achievement in the stable discharge in an AC-PDP by means of the panel-aging process strongly depends on whether the surface morphologies of the MgO thin film are identical on both the ITO and bus electrodes. It is also found that the self-erasing discharge during the panel-aging process is not effective in obtaining the uniform surface morphology of the MgO thin film on the ITO and bus electrodes, due to the difference in the amount of ion bombardment on the ITO and bus electrodes caused by the erasing of the wall charges during the self-erasing discharge. These experimental results are confirmed by monitoring the three-dimensional IR emission and simulating the wall charge distribution, the electric field strength, and the impulse on the MgO layer.     

Structural and discharging properties of MgO thin films prepared by pulsed laser deposition

In this work, pulsed laser-deposited thin films of MgO were studied for application in plasma display panels. The firing voltage (FV) of discharge cells with MgO films was measured and the film structure was investigated as a function of film deposition conditions. MgO thin films were deposited at oxygen pressure and substrate temperature between 0.02-5 Pa and 260-600 °C, respectively. The structure of thin films was investigated by using X-ray diffraction, X-ray reflection and atomic force microscopy methods. It was found that the FV is strongly correlated with the film deposition conditions and structural properties. In general, the FV values were smaller for the films with higher crystallinity and density. The crystallinity and the density of the films increased when the deposition temperature was raised and the O₂ pressure was reduced. The lowest FV values (~ 120 V) were obtained at the growth temperature of 550 °C and at O₂ pressures below 1 Pa.     

High tunnel magnetoresistance in epitaxial Co/sub 2/Cr/sub 0.6/Fe/sub 0.4/Al/MgO/CoFe tunnel junctions

We have fabricated fully epitaxial magnetic tunnel junctions (MTJs) using a Co-based full-Heusler alloy Co/sub 2/Cr/sub 0.6/Fe/sub 0.4/Al (CCFA) thin film and an MgO tunnel barrier. The CCFA thin film for the lower ferromagnetic electrode was deposited by magnetron sputtering on an MgO-buffered MgO single-crystal substrate, and the MgO tunnel barrier was formed by electron beam evaporation. The microfabricated epitaxial CCFA/MgO/CoFe MTJs showed high tunnel magnetoresistance ratios of 42% at room temperature and 74% at 55K.     

Dependence of the MgO sputtering power on the characteristics of MgZnO thin films grown by radio-frequency magnetron sputtering

The dependence of the MgO sputtering power on the structural and optical properties of epitaxially grown MgZnO thin films on GaN/sapphire substrates by radio-frequency magnetron sputtering was investigated. The photoluminescence investigation showed blue shift of 170 meV in MgZnO film grown at the MgO power of 300 W, compared with the ZnO films grown at the MgO power of 0 W, which was attributed to the enhancement of the Mg incorporation at higher power. In addition, increase in Mg mole fraction with increase in sputtering power of MgO was observed from the PL results, and a maximum of 6.6 at.% Mg was obtained at the MgO power of 300 W. The high-resolution X-ray diffraction and transmission electron microscopy (TEM) investigations revealed that the threading dislocation density in the MgZnO thin films increased with increase in sputtering power. Furthermore, microstructural analysis performed by TEM revealed formation of a thin cubic-like phase in the interface between GaN template and MgZnO thin film, together with increased thickness of the interfacial layer with sputtering power.     

c轴取向PbTiO3外延生长的研究

本文研究了ＭＯＣＶＤ法淀积过程中工艺条件对ＰｂＴｉＯ３膜ｃ轴取向度的影响，探讨了ＰｂＴｉＯ３膜的生长过程，通过调节氧气流量首次在ＭｇＯ（１００）单晶衬底上淀积出ｃ轴取向的ＰｂＴｉＯ３外延膜。ＰｂＴｉＯ３外延膜的介电常数为９０，折射率为２．６４，均和单晶性能一致。     

Microstructural,optical and electrical properties of various time annealed spin coated MgO thin films

In the present study, we have reported on the effect of annealing time variations for spin coated magnesium oxide (MgO) thin films. The various time annealed MgO thin films structural, surface morphological, compositional, electrical and optical absorption properties were studied by X-ray diffraction, scanning electron microscopy, energy dispersive analysis by X-rays, I–V studies and UV–vis spectroscopy, respectively. The cubic structure formation with preferential orientation along the (200) plane was confirmed from structural analysis. In addition, the influence of the annealing on the microstructural properties of MgO was plausibly explained. The optical properties of MgO thin films were estimated using the transmission spectrum in the range of 400–800 nm. The optical band gap energy of MgO thin films was found to be in the range between 3.81 and 3.93 eV. The morphological studies depicted that the spherical and ellipsoid shaped grains were distributed evenly over the entire surface of the film. The sizes of the grains are found to be in the range between 200 and 250 nm. The composition analysis was performed by EDX for various temperatures annealed MgO thin films.