离子束反应溅射ZnO薄膜的晶体结构及光学、电学性质研究

采用离子束反应溅射法在玻璃基片上沉积了一系列ZnO薄膜样品.通过对薄膜样品XRD谱的分析,发现基片温度和溅射氧分压是同时影响ZnO薄膜沿c轴择优取向生长的重要因素.在基片温度350 ℃,氧分压1.3 的溅射条件下,得到了完全沿c轴取向生长的只有(002)晶面的ZnO薄膜.薄膜的吸收光谱测量结果表明,基片温度和氧分压对ZnO薄膜的光学禁带宽度有重要影响.不同氧分压、不同基片温度制备的薄膜电阻率相差很大.     

Magnetoresistance in ZnO induced by spin-splitting and weak localization

ZnO thin films were deposited on silicon wafers by magnetron sputtering, with electron concentrations ranging from 8.6 × 10¹⁸ to 6.1 × 10¹⁹ cm⁻³. The magnetoresistance (MR) of ZnO was studied experimentally and theoretically. It is found that the MR of ZnO is anisotropic, and strongly dependent on temperature and the electron concentration. The sample with the lowest electron concentration shows positive MR at 2 K and negative MR at higher temperatures, while other samples with higher electron concentrations present negative MR at all temperature. The positive MR is attributed to the spin splitting of the conduction band induced by the exchange interaction. The negative MR is related to the suppression of the weak localization when magnetic field is applied. A model of superposition of positive and negative MR was employed to simulate the experimental data. Excellent agreement is achieved between experiment and simulation, and the anisotropy of MR is well explained by the superposition model as well.     

Morphological,Optical and DC Conduction Properties of a-GaSe Semiconductor Nanoparticle Thin Films

Amorphous gallium selenide （a-GaSe） semiconductor nanoparticle thin films were deposited onto well cleaned glass substrates by inert gas condensation （IGC） technique under a vacuum of 400 x 10-6 Pa （3 x 10-6 Torr）. The films were characterized by different structural and optical techniques, including X-ray diffraction, field emission scanning electron microscopy （FESEM）, field emission transmission electron microscopy （FETEM）, UV-visible absorption spectroscopy and I-V measurements. The particle size and size distribution were determined by TEM images which show the presence of spherical particles in the range of 5-50 nm in size. SEM images indicate that the a-GaSe film grown on glass substrate is almost smooth and dense. The optical properties of a-GaSe nanoparticle thin films were determined by optical absorption spectra. The optical bandgap of the film was estimated to be 2.19 eV and the transitions are allowed direct type. The electrical conductivity of the deposited films has been studied as a function of temperature. In the higher temperature range the dominance of thermally activated band conduction was observed; whereas in the low temperature ranqe the hoppinQ conduction in the band tails of localized states was found to be dominated.     

ZAO透明导电薄膜的制备及性质

ZAO（ZnO：Al）透明导电薄膜是一种具有高的载离子浓度和宽禁带的半导体氧化物，电学和光学性能优异。极具应用前景。本文介绍了ZAO薄膜的制备现状、特性、磁控溅射参数对其电学和光学性质的影响以及今后研究的方向。     

Increased cycling stability of AlPO4-coated LiMn2O4 for lithium ion batteries

AlPO₄ was used to the surface modification of LiMn₂O₄ by chemical deposition method to improve the cycling stability of LiMn₂O₄ at ambient and elevated temperature. The uncoated and AlPO₄-coated LiMn₂O₄ materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electrochemical test. While the uncoated LiMn₂O₄ showed 17.9% and 32.9% capacity loss in 50 cycles at 30 °C and 55 °C, respectively, the AlPO₄-coated LiMn₂O₄ only exhibited the capacity loss of 2.6% and 7.6% at 30 °C and 55 °C, respectively. The dQ/dV versus potential plots at 55 °C revealed that the improvement in cycling performance of the coated-LiMn₂O₄ electrode is attributed to the stabilization of the spinel structure by the presence of AlPO₄ on the surface of LiMn₂O₄.     

基于溶胶凝胶法的二氧化锡复合薄膜的制备及表征

以金属无机盐SnCl2.2H2O、CuCl2.2H2O和无水乙醇为原料,用溶胶凝胶法制备了SnO2和CuO掺杂的CuO-SnO2薄膜,并用X射线衍射、扫描电镜、透射电镜和电化学工作站对样品进行了表征。结果表明:随着退火温度的增加,薄膜结晶性变好,晶粒长大,电学特性增强,最佳退火温度确定为450℃。掺杂CuO的SnO2薄膜导电性好于同等条件下未掺杂的SnO2薄膜。SnO2呈四方相金红石结构,衍射峰显示薄膜中存在部分SnO。聚乙二醇的添加增强了SnO2的衍射峰,当超过一定添加量后将抑制晶粒的生长,并使得CuO-SnO2薄膜的导电性呈先减小后增大的趋势。丙三醇的添加可极大改善薄膜的表面形貌,增强了SnO2的衍射峰,且导电性明显变好。     

GDARE法制备不同厚度ZnO薄膜的热电性质

以气体放电活化反应蒸发(GDARE)沉积法通过多次沉积制备不同厚度ZnO薄膜。原子力显微镜和X射线衍射测试分析表明,所得ZnO薄膜具有纳米颗粒多晶结构,粒径在30~70 nm,晶粒尺寸随薄膜厚度增加而增大,不同厚度的薄膜均具有高度的c轴取向性。由GDARE法沉积的ZnO薄膜具有较高的温差电动势率S(Seebeck系数),厚度200 nm的薄膜在440K附近S可达600μV/K。相同温度下,薄膜的温差电动势率S与电阻率ρ均随着膜厚的增加而减小。在考察了薄膜电阻率与温差电动势率的综合影响后,得到在440 K附近,厚度为600 nm的ZnO薄膜具有相对最优秀的热电性能。讨论了ZnO薄膜的表面电传导过程及温差电动势产生机制。     

Fiber texture of sputter deposited molybdenum films and structural zone model

The texture orientation of 2.5, 5, and 100 nm thick Mo films grown by sputter deposition on SiO₂ membranes at room temperature has been studied quantitatively using transmission electron microscopy. The sample tilt angle dependent diffraction patterns of these films revealed a fiber texture with the [110] out-of-plane direction for all film thicknesses. Films grown at different sputtering power and substrate–target distance showed a similar texture orientation. These results would imply that the growth was in zone II, according to the microstructure classification of the structural zone model. This is in contrast to the conventional assignment of zone I for Mo deposition at room temperature based on the low Mo homologous temperature of ∼0.1. It was found that texture dispersion was reduced as the thickness of the film increased. Possible mechanisms, including energetic particles bombardment during growth, which could affect the surface mobility and texture of the films, were discussed.     

磁控溅射TiO2膜的真空度对薄膜亲水性影响的实验研究

采用反应溅射技术可以制备出具有亲水作用的TiO2薄膜。这种TiO2薄膜断面呈现柱状晶体结构。薄膜表面出现不规则起伏。薄膜的晶相主体均为锐钛矿型。TiO2薄膜的光透射谱变化不大。这种TiO2薄膜经紫外光辐照后,可以降低水和TiO2薄膜表面之间的接触角。不同工艺条件下制备的TiO2薄膜接触角相差很大。在纯氧条件下,薄膜制备的真空度对薄膜的亲水性有着决定性的影响。     

磁控溅射制备纳米TiO2薄膜光催化降解苯酚的研究

采用射频磁控溅射方法分别在玻璃、A1片和ITO玻璃上制备出性能优良的TiO2纳米薄膜,研究了薄膜光催化性能.通过XRD、SEM和UV-Vis吸收光谱对薄膜进行表征,研究了不同退火温度和不同衬底对薄膜光催化性能的影响.结果表明:薄膜经500℃退火处理,TiO2由非晶转变为锐钛矿结构,并且退火后薄膜的紫外吸收波长发生红移,光催化降解性能提高;比较玻璃、ITO玻璃和A1为衬底制备的TiO2薄膜,以A1片为衬底的TiO2薄膜,由于形成Schottky势垒,光催化性更好.     

离子束溅射作用下聚四氟乙烯薄膜的制备方法

在多功能离子束辅助沉积装置上采用交替溅射和冷却聚四氟乙烯靶材的方法制备了薄膜。由XPS的结果可知，所得薄膜主要由CF2结构组成；FT-IR的结果表明，所得薄膜由C-F的最强吸收峰和聚四氟乙烯的特征吸收峰构成。所得薄膜的这些结构特征与聚四氟乙烯的结构是一致的。试验结果表明，用这种离子束溅射沉积方法可以获得聚四氟乙烯薄膜。     

La-doped Copper Nitride Films Prepared by Reactive Magnetron Sputtering

Copper nitride film (Cu3N) and La-doped copper nitride films (LaxCu3N) were prepared on glass substrates by reactive magnetron sputtering of a pure Cu and a pure La targets under N2 atmosphere. The results show that La-free film was composed of Cu3N crystallites with anti-ReO3 structure with (111) texture. The formation of the LaxCu3N films is affected strongly by La, and the peak intensity of the preferred crystalline [111]-orientation decreases with increasing the concentration of La. High concentration of La may prevent the formation of the Cu3N from crystallization. Compared with the Cu3N films, the resistivity of the LaxCu3N films have been decreased.     

中频反应磁控溅射TiO2薄膜对敌敌畏的光催化降解性能

作者利用中频反应磁控溅射技术制备了厚度低于 4 0 0nm的TiO2 薄膜 ,并对其在紫外线作用下对敌敌畏 (DDVP)的光催化降解性能进行了系统的研究。实验结果显示 :敌敌畏的降解速率与光照时间和紫外辐照强度成正比 ,在TiO2 薄膜催化下 ,12 5W紫外灯辐照 4h后降解率可达 97%。 30 0℃下退火处理有利于提高薄膜的催化能力。薄膜厚度的增加亦可提高其催化能力     

不同厚度纳米Ti薄膜的力学性能

通过直流磁控溅射方法制备出四个不同厚度的纳米Ti薄膜,并分别采用纳米压痕仪、电子薄膜应力分布测试仪研究了Ti薄膜的力学性能和残余应力大小,结合分形维数方法和原子力显微镜对薄膜表面粗糙度和表面形貌进行了分析。实验结果表明:随Ti薄膜厚度的增加,薄膜晶粒尺寸逐渐增大,表面粗糙度和残余应力值随厚度的增加先增大后减小,而Ti薄膜弹性模量和硬度随薄膜厚度增加呈现出先减小随后增大的趋势。当薄膜厚度为600,2400,3600nm时薄膜中存在残余压应力,厚度为1200nm时存在残余拉应力,薄膜中残余应力分布最为均匀,但此时薄膜具有较低的硬度和弹性模量值。分析得出Ti薄膜中存在残余拉应力会使薄膜硬度和弹性模量值变小,残余压应力反之。     

AFM Studies of Platinum Silicide Thin Films on Silicon Grown by Pulsed Laser Deposition

PtSi ultra-thin films were grown on Si-wafer using pulsed laser deposition(PLD).The surface structure of these films was studied by atomic force microscopy(AFM).In addition ,the compositional structure of the PtSi as deter-mined from X-ray photoelectron spectroscopy(XPS)is discussed.First report of a possible growth mechanism is presented, on studying the variation of morphological features(i,e,roughness and size of crystallites)with annealing temperatures and the film thicknesses..     

Effects of High Magnetic Field on the Structure and Magnetic Properties of Molecular Beam Vapor Deposited Fe₆₀Ni₄₀ Thin Films

The Fe₆₀Ni₄₀ (in atomic %) polycrystalline thin films with 90 nm thickness were prepared on 200 °C quartz substrate by using molecular beam vapor deposition method. The influence of 0 T and 6 T magnetic fields on the structural evolution and magnetic properties of thin films was studied by using EDXS, XRD, AFM and VSM. In this study, only α phase was formed in both thin films. It was found that the application of a 6 T magnetic field obviously decreases the RMS of surface roughness and the grain size. For the magnetic properties of the thin films, the 6 T magnetic field increases the saturation magnetism Ms in-plane and the squareness (Mr/Ms) of the hysteresis loop and decreases the coercive force Hc. This indicates the soft magnetic properties of the thin films have been notably enhanced in-plane by a high magnetic field. The relationship between the structural evolution and magnetic properties was discussed in details.     

热蒸发法制备SnS薄膜及其表征

用热蒸发技术在ITO玻璃基片上沉积SnS薄膜.通过对该薄膜进行结构、成分和表面形貌分析,表明它是具有正交结构的SnS多晶薄膜;相对于恒电流电沉积法制备的SnS薄膜来说,该薄膜颗粒更细,粒径在(60～100) nm,并且它的均匀性和对基片的附着力也更好.通过测量薄膜样品的反射和透射光谱,得到其直接禁带宽度Eg=1.34 eV,在基本吸收边附近的吸收系数大于2×104 cm-1.该薄膜的导电类型为p型,电阻率的数量级为10-2 Ω·cm.因此,用热蒸发技术制备出的SnS薄膜的质量和性能都比较理想,该薄膜非常适合做太阳能电池的吸收层.     

溶剂热法快速合成纯相FeS_2黄铁矿光电材料

FeS2黄铁矿具有较高的光吸收系数和合适的禁带宽度,与太阳光谱匹配性较好,是一种具有极大潜力的光电材料,其相纯度对光伏电池的效率有显著影响。本文基于溶剂热法,采用油胺-油酸双配体体系,实现纯相FeS2黄铁矿的快速合成。通过反应温度和反应时间的考察,可知该工艺路线具有合成温度宽和反应时间短等优点。通过反应溶剂、添加剂及含量等参数的进一步考察,获得了更小颗粒尺寸的纯相FeS2黄铁矿,并对应分析了其变化机理。     

硫化温度对FeS2薄膜的晶体结构和光电性能的影响

本文用磁控溅射法制备的纯Ｆｅ 膜,再在Ｓ气氛中（８０ｋＰａ）于不同的温度下（２００～６００℃）进行热硫化,硫化时间为１０ｈ,使其转变成为ＦｅＳ２薄膜,并研究了硫化温度对转变形成的ＦｅＳ２薄膜晶体结构、化学成分、组织形貌和光电性能的影响规律。