NH3气氛处理制备p型ZnO薄膜及性能表征

采用NH₃气氛处理直流/射频共溅射方法制得的ZnO：Al薄膜，从而获得Al+N共掺p型ZnO薄膜.XRD，场发射扫描电子显微镜测试及Hall效应测试发现，处理温度对ZnO薄膜的结构和电学性能具有较大的影响，其中处理温度为700℃时，薄膜具有较好的c轴择优取向，并且薄膜表面平整，结构紧密，晶粒大小均匀，无明显空洞和裂缝，具有良好的表面质量，晶粒尺寸约为40—60nm，薄膜的导电类型由n型转变为p型.     

NH3气氛处理制备p型ZnO薄膜及性能表征

采用NH₃气氛处理直流/射频共溅射方法制得的ZnO：Al薄膜,从而获得Al+N共掺p型ZnO薄膜.XRD,场发射扫描电子显微镜测试及Hall效应测试发现,处理温度对ZnO薄膜的结构和电学性能具有较大的影响,其中处理温度为700℃时,薄膜具有较好的c轴择优取向,并且薄膜表面平整,结构紧密,晶粒大小均匀,无明显空洞和裂缝,具有良好的表面质量,晶粒尺寸约为40—60nm,薄膜的导电类型由n型转变为p型. 关键词： p型ZnO Al+N共掺杂 直流/射频共溅射     

埋藏于有机介质中金属原子团的结构研究(I)

利用双源同时蒸发和U型管热壁蒸发法制备了两种金属-有机复合薄膜Ag-7,7,8,8-tetracyanoquinodimethane和Ag-1,4-bis-(1,1-dicyanovinyl)-benze.利用透射电子显微镜和可见—紫外光谱研究了所制备的金属-有机复合薄膜的结构特性，发现它们是一种金属原子团埋藏于具有π-共轭体系的有机介质中的薄膜体系. 关键词：     

金属离子掺杂对TiO2/白云母纳米复合材料中TiO2的颗粒形态及相组成的影响

采用化学液相沉积法制备了系列未掺杂和掺杂不同金属离子的TiO2白云母纳米复合材料.利用扫描电子显微镜(SEM),x射线衍射(XRD)对其TiO2薄膜的TiO2颗粒形态和相组成进行了详细研究.结果表明,TiO2颗粒在15—50nm之间;除球形颗粒外,掺杂Mn2+,Zn2+的样品中还出现有金红石柱状颗粒.TiO2薄膜中相组成以锐钛矿、金红石共存为特征;掺杂金属离子对TiO2相组成的影响取决于金属离子的离子半径、电荷及配位体特征. 关键词： 金属离子掺杂 TiO2 颗粒形态 相组成     

纳米硅薄膜的生长动力学与计算机模拟

氢化纳米硅(nc-Si:H)薄膜由于其具有奇异的结构和独特的性质,而引起广泛的关注.本文在等离子体增强化学气相淀积(PECVD)系统中,以高纯H₂高度稀释SiH₄为反应气体源,在射频和直流双重功率源的激励下制备成功具有纳米结构的nc-Si:H薄膜.利用高分辨率电子显微镜(HREM)、Raman散射谱(RSS)、扫描隧道电子显微镜(STM)等实验技术对nc-Si:H薄膜样品作了研究.基于对薄膜制备过程的动力学分析,提出nc-Si:H薄膜的分形生长模型:扩散与反应限 关键词：     

Ag-Sn金属薄膜在升温过程中的结构变化

借助TEM和HVEM观察了碳膜上Ag-Sn薄膜在加热到640℃的过程中的结构变化。升温到200—250℃时,Ag和Sn迅速反应变为γ相Ag₃Sn。γ相在480℃以上迅速转变成具有片层状组织的β相。在510℃左右,β相薄膜开始产生缩聚。还用扫描电子显微镜观察了GaAs基底上Ag-sn膜加热后的表面形态。结果表明,若Sn含量(20—65Wt％)越多、合金温度越高,则合金膜表层缩聚越严重。 关键词：     

用热丝CVD技术制备场发射冷阴极金刚石薄膜

以甲烷和氢气的混合气体为原料,用热丝化学汽相淀积法,在(100)硅衬底上800℃温度时异质生长出适合场发射的金刚石薄膜.然后用扫描电子显微镜、X射线衍射仪、透射电子显微镜和喇曼光谱仪等对其进行了分析,结果表明,所制备的薄膜是多晶金刚石,而且在(111)晶相择优生长.在扫描电子显微镜下(111)晶粒的外形几乎都是四面体结构,具有很多尖端,可以加强一定电压下的电场,所以所制备的薄膜能够满足低压场发射的要求.     

溶胶—凝胶法制备SiO2基片Er^3＋：Al2O3光学薄膜

用溶胶—凝胶法在SiO2基片上提拉制备了掺Er^3 ：Al2O3光学薄膜。采用扫描电子显微镜、原子力显微镜、差热—热重分析仪、X射线衍射仪研究了掺Er^3 ：Al2O3光学薄膜的肜貌和结构特性。在900℃烧结后，SiO2基片上提拉15次形成厚度8μm掺摩尔比0．01Er^3 的面心立方结构γ-Al2O3薄膜具有明显(110)择优取向，掺摩尔比0．01Er^3 对γ—Al2O3的品体结构和结晶生长过程木产生显著影响。薄膜具有均匀多孔结构，平均粒径为30～100nm，平均孔径为50～100nm，表面起伏度为10～20nm。掺摩尔比0．01Er^3 ：rAl2O3薄膜，获得了中心波长为1．534μm(半峰全宽为36nm)的光敛发光谱。     

脉冲偏压电弧离子镀TiO2薄膜的力学与光学性能

用脉冲偏压电弧离子镀技术在玻璃基片上制备均匀透明的TiO₂薄膜.利用X射线衍射仪、原子力显微镜、扫描电子显微镜、紫外-可见透射光谱仪和纳米压痕仪等手段,对不同脉冲负偏压下合成薄膜的相结构、微观结构、表面形貌、力学和光学性能进行表征.结果表明，沉积态薄膜为非晶态.脉冲负偏压对薄膜性能有明显的影响.随偏压的增加，薄膜厚度、硬度和弹性模量均先增大后减小，前者峰值出现在100—200 V负偏压范围，后两者则在250—350V范围.300 V负偏压时薄膜硬度最高，薄膜达到原子级表面光滑度，均方 关键词： 2薄膜')" href="#">TiO₂薄膜 脉冲偏压电弧离子镀 硬度 折射率     

纳米多孔金薄膜显微结构分析

 采用亚硫酸金钠为主盐,在阳极氧化铝模板上进行了化学镀和电镀金实验研究。通过扫描电子显微镜和X射线衍射分析测试表明:采用以上两种方法均能制备出纳米多孔金薄膜。两种方法制备的多孔金薄膜微观结构存在较大的差异。化学镀制备的多孔金薄膜微观上是枝晶状的,电镀制备的多孔金薄膜微观上由纳米线构成。     

氮化硅薄膜的微结构

利用TEM,STM和PDS显微光度计研究了ECR-PECVD技术制备的Si₃N₄薄膜的微结构.结果表明：在较低沉积温度下，ECR-PECVD制备的Si₃N₄薄膜是一种纳米α-Si₃N₄薄膜，其晶粒粒度在14—29nm间，而且这种薄膜具有较好的表面平整度.初步分析了ECR-PECVD制备的Si₃N₄在较低沉积温度下形成晶态薄膜的机理. 关键词：     

Laser‐Induced Self‐Assembled Nanostructures on Electron‐Transparent Substrates

Currently, one of the challenges in high‐resolution transmission electron microscopy (TEM) studies of nanomaterials is to make contamination‐free materials in a simple and time‐efficient way. Here, a method is demonstrated that combines nanosecond‐pulsed laser dewetting of thin films with a film float‐off technique to realize nanostructures (NSs) on electron‐transparent substrates in a robust and rapid manner. NSs of metal (Ag) and bimetals (AgCo, AuCo) ranging from 20 to 150 nm are synthesized on thin carbon film deposited on mica substrates. The NS/carbon system is subsequently transferred onto TEM grids by a float‐off process resulting from debonding of the carbon from mica due to their contrasting hydrophobic nature. This process enables the fabrication of different NSs on flexible and electron‐transparent substrates.     

Molecular crystallization of rubrene thin films assisted by gold nanoparticles

We demonstrate that crystalline organic rubrene thin films can be obtained by a facile spin-coating method using gold (Au) nanoparticles (NPs). Dodecanethiol-functionalized Au NPs were dissolved with rubrene molecules in solvent and a thin film of Au/rubrene was prepared by a simple spin coating process. The results of confocal photoluminescence (PL) and absorption spectral mapping confirmed the local formation of orthorhombic crystalline structures of the Au/rubrene hybrid film, in contrast to the monoclinic structure of plain rubrene films. Further, the results of transmission electron microscopy (TEM) and X-ray diffraction analysis, as well as Raman spectroscopy measurements of the rubrene and Au/rubrene films suggested the formation of high crystalline Au/rubrene film. The molecular crystallization of the Au/rubrene hybrid film is attributed to the nucleation effect of the Au NPs.     

等离子增强原子层沉积低温生长AlN薄膜

采用等离子增强原子层沉积技术在单晶硅基体上成功制备了AlN晶态薄膜, 利用椭圆偏振仪、原子力显微镜、小角掠射X射线衍射仪、高分辨透射电子显微镜、 X射线光电子能谱仪对样品的生长速率、表面形貌、晶体结构、薄膜成分进行了表征和分析, 结果表明, 采用等离子增强原子层沉积制备AlN晶态薄膜的最低温度为200 ℃, 薄膜表面平整光滑, 具有六方纤锌矿结构与(100)择优取向, Al_2p与N_1S的特征峰分别为74.1 eV与397.0 eV, 薄膜中Al元素与N元素以Al-N键相结合, 且成分均匀性良好. 关键词： 氮化铝 等离子增强原子层沉积 低温生长 晶态薄膜     

薄膜生长荧光显微图像实时采集与分析系统

设计了一套具有一定实用意义和科学价值的薄膜生长荧光显微图像实时采集与分析系统,可以实现透明衬底上有机荧光分子薄膜生长的实时原位监测。进一步阐明了系统的硬件构筑思路和软件设计架构,并依据薄膜的形貌特征,给出8个主要生长信息参数及其求取算法,并利用自行搭建的实验系统,针对联六苯(p-6P)分子在云母衬底上的纳米纤维生长过程,得出了其准一维的线性生长规律。该系统作为重要的薄膜生长成像监测技术,有望在薄膜与衬底表面相互作用和衬底微区结构特性研究等方面起到积极的作用。     

Fabrication of micro/nano crystalline ITO structures by femtosecond laser pulses

A method is proposed for the fabrication of micro/nano crystalline indium tin oxide (c-ITO) structures using a Ti:Sapphire laser with a repetition rate of 1 kHz and a wavelength of 800 nm. In the proposed approach, an amorphous ITO (a-ITO) thin film is transformed into a c-ITO micro/nano structure over a predetermined area via laser beam irradiation, and the residual a-ITO thin film is then removed using an etchant solution. The fabricated c-ITO structures are observed using scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (TEM). The observation results show that the use of a low repetition rate laser induces a high thermal cycling effect within the ITO film and therefore prompts the formation of micro-cracks in the c-ITO structure. In addition, it is shown that as the laser power approaches the ablation threshold of the a-ITO thin film, nanogratings and disordered nanostructures are formed along the center lines of the c-ITO patterns formed using linearly polarized and circularly polarized laser beam irradiation, respectively. The nanogratings are found to have a period of approximately 200 nm (i.e. one-quarter of the irradiation wavelength), while the nanostructures have an average diameter of approximately 100–160 nm.     

Substrate-target distance dependence of structural and optical properties in case of Pb(Zr,Ti)O3 films obtained by pulsed laser deposition

The paper presents the influence of pulsed laser deposition (PLD) parameters on the structural and optical properties of PZT thin films grown on platinum substrate. X-ray diffraction (XRD), spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS) are used to determine the thin film properties. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) are employed to get additional information. By changing the distance between target and substrate, different crystalline orientations of PZT are obtained. The thin film thickness and its roughness, as well as the refractive index are also influenced by the chosen distance.     

Efficient field emission from coiled carbon nano/microfiber on copper substrate by dc-PECVD

Crystalline coiled carbon nano/micro fibers in thin film form have been synthesized via direct current plasma enhanced chemical vapor deposition (PECVD) on copper substrates with acetylene as a carbon precursor at 10 mbar pressure and 750 °C substrate temperature. The as-prepared samples were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). XRD pattern as well as selected area electron diffraction (SAED) pattern showed that the samples were crystalline in nature. SEM and HRTEM studies showed that as synthesized coiled carbon fibers are having average diameter ∼100 nm and are several micrometers in length. The as-prepared samples showed moderately good electron field emission properties with a turn-on field as low as 1.96 V/μm for an inter-electrode distance 220 μm. The variation of field emission properties with inter-electrode distance has been studied in detail. The field emission properties of the coiled carbon fibrous thin films are compared with that of crystalline multiwalled carbon nanotubes and other carbon nanostructures.     

Growth of AlN nanostructures by a rapid thermal process

Aluminum nitride nanorods were grown during rapid thermal annealing of multi-layered Al₂S₃ /BaS thin films. Depending on the thickness ratio between the BaS and Al₂S₃ layers, nanowires or straight nanorods were obtained. Typical dimensions for the nanorods were a diameter in the range of 50-100 nm and a length of 2-5 μm. The nanostructures are formed upon annealing at a relatively low temperature of 900 ^°C when aluminum evaporates from the thin film, but remains trapped between the thin film surface and the Si wafer, which is used as a support during the annealing. The nitrogen is provided by N₂ gas flushed through the annealing chamber. High-resolution transmission electron microscopy showed crystalline, wurtzite-structured AlN nanorods. The growth mechanism in terms of thin film composition, annealing parameters and the role of catalysts is discussed.     

通过具有偏振选择性的紫外/红外混频超快光谱探测有机光电薄膜中的相对分子取向

分子堆积模式是决定电子/能量转移过程的关键因素,影响有机薄膜器件的光电特性. 本文通过具有偏振选择性的紫外/红外混频超快光谱研究了7-(二乙氨基)香豆素-3-羧酸和苝两种有机分子的薄膜. 并利用分子间能量/电子转移引起的信号各向异性变化来计算供体的电子跃迁偶极矩与受体的振动跃迁偶极矩之间的夹角,从而得出两个相邻分子之间的相对取向. 用这种方法测得7-(二乙氨基)香豆素-3-羧酸薄膜的相对取向角为53.4o,接近其单晶结构的60o,苝薄膜的相对取向角为6.2o,也接近其单晶结构的-0.2o. 除了实验中的不确定性,这种方法确定的角度与单晶的角度之间的微小差异还可能源于薄膜样品是多晶的,且其中一些分子是无定形的.