Deposition of ZnO Films on Freestanding CVD Thick Diamond Films

For ZnO/diamond structured surface acoustic wave （SAW） filters, performance is sensitively dependent on the quality of the ZnO films. In this paper, we prepare highly-oriented and fine grained polycrystalline ZnO thin films with excellent surface smoothness on the smooth nucleation surfaces of freestanding CVD diamond films by metal organic chemical vapour deposition （MOCVD）. The properties of the ZnO films are characterized by x-ray diffraction （XRD）, scanning electron microscopy （SEM）, and photoluminescence （PL） spectrum. The influences of the deposition conditions on the quality of ZnO films are discussed briefly. ZnO/freestanding thick-diamond-film layered SAW devices with high response frequencies are expected to be developed.     

超分子有机薄膜

利用超分子有机薄膜技术能制成新的传感分子电子器件、光学器件和生物分子器件等，受到跨学科高技术研究领域的重视。本文描述了超分子有机薄膜的制备方法以及在各应用领域的研究状况。重点介绍了我们研究组在近20年工作中，利用LB膜技术，在光电器件、气体传感技术和光学非线性，特别是在生物传感技术方面的研究成果。按照生物体系提供的信息，模拟合成功能分子，建造有组织的分子组装体，以便用来研究依赖于分子排列的生物物理化学效应。     

氟掺杂的氧化锌薄膜的结构和光学特性

通过热氧化氟化锌(ZnF2)薄膜的方法制备出氟掺杂的多晶ZnO薄膜,ZnF2薄膜是利用电子束蒸发方法沉积在Si(100)衬底得到的。利用X射线衍射和X射线电子能谱研究了ZnF2薄膜向ZnO的转变过程。实验结果表明,在400℃退火30min的条件下能够获得六方纤锌矿结构的ZnO：F薄膜。对ZnO：F薄膜的室温光致发光谱可以观察到位于379nm、半峰全宽为73meV的紫外发射峰,而相应于缺陷的深能级发射则完全猝灭。表明ZnO中残留的F能够有效地增强激子的发光,同时使缺陷发光强度明显降低。对F掺杂对ZnO的发光性能的影响进行了讨论。     

Durability of Ultra-Thin Silver Films and Silver-Gold Alloy Films under UV Irradiation

Silver films(Ag) and silver-gold films(Ag-Au) with thickness ~15nm are coated on Bk7 glasses through thermal evaporation.After doping gold of 5.2%,the grain size of the Ag film reduces from 13.6nm to 9.1nm,also the surface roughness decreases from 1.45 nm to 0.94 nm.A UV lamp is used as the irradiation light source to accelerate the corrosion process in the atmosphere.After 17 h irradiation,the pure silver film surface turns dark,and the transmittances reduce from 350 nm to 500 nm,while the Ag-Au film degrades much less,almost negligibly after UV radiation.Additional x-ray photoelectron spectroscopy and atomic force micrographs data are provided to show atomic content of Sims and their surface morphologies.It is suggested that small grain size and high packing density of alloy film prevent reaction of silver with oxygen in the atmosphere,which leads to high stability of the Ag-Au Elm.     

Fabrication Techniques and Characteristics of Ultra-Thin Optical Polarizing Films Using Gold Island Films

Fabrication techniques of ultra-thin optical polarizing films using gold island films have been investigated for the near-infrared region. The polarizing films are fabricated by stretching the periodic multilayers consisting of gold island layers and glass layers. We have experimentally investigated the optimum fabricating conditions necessary to induce large optical anisotropy into the gold island layers and have formed submicrometer-thick polarizing films with an extinction ratio of ≥20 dB in a near-infrared region longer than 800 nm. These polarizing films could be useful micro-polarizers for fiber-embedded in-line optical devices, micro-optics, and hybrid integrated optics.     

薄膜的光谱发射率

本文讨论了薄膜内的多次反射对低吸收薄膜光谱发射率的影响。这里推导出的薄膜发射率的表达式与薄膜厚度d和其光学常数n(λ）和k(λ）有关。在d→∞的特殊情况下，薄膜发射率与大块材料发射率相等。给出了实际数值评价及发射率与d、n(λ）和k(λ)相互关系的更为精确的数值结果。     

Tribological Properties of MACs-APS Films

Multiply-alkylated cyclopentanes (MACs) with different molecular structure were deposited on single crystal silicon wafers coated with a thin aminopropyltrimethoxylsilane (APS) film as an adhesive layer to form MACs-APS films. The thickness, wetting behavior and nano-scale morphologies of the films were characterized by means of ellipsometry, contact angle measurement, and atomic force microscopy (AFM). The friction and wear behaviors of the thin films sliding against a Si₃N₄ ball were examined on a UMT-2MT tribometer in a ball-on-disk contact mode. The worn surfaces of the MACs-APS films and the counterpart Si₃N₄ balls were investigated with a scanning electron microscope (SEM). It was found that the water contact angles on the MACs-APS film increased with the MACs alkyl chain-length. The MACs-APS film exhibited higher load-carrying capacity and better friction reduction and anti-wear behavior as compared with the APS film. This is suggested to occur because the APS acts as a strongly bonded lubricant phase and MACs as a mobile lubricant phase in the MACs-APS film. The increase of the chain-length of the alkyl substituent in the MACs compounds resulted in improved tribological properties of MACs-APS film. It is suggested that the longer alkyl chains are much more flexible and can dissipate the mechanical energy during the shearing process more easily than the short chain compounds. MACs with the longer chains have stronger chain-chain interactions and the larger MAC molecules have stronger intermolecular interactions, resulting in the good tribological properties of MACs-APS film.     

氮化钛薄膜的光学性能分析

利用磁控溅射法，在不同的工艺条件下制备氮化钛薄膜。详细分析了不同工艺条件下薄膜的光谱选择特性以及相应的光学常数，通过俄歇电子能谱对薄膜的不同深度的元素成分进行了分析，由原子力显微镜测量并处理得到氮化钛薄膜的表面形貌图。结果表明，氮化钛薄膜的光学性能严格依赖于氮和钛原子数比，符合化学计量比的TiN薄膜具有良好的光谱选择性。基底加负偏压溅射可进一步改善薄膜的性能。     

Critical Dynamics in Thin Films

Critical dynamics in film geometry is analyzed within the field-theoretical approach. In particular we consider the case of purely relaxational dynamics (Model A) and Dirichlet boundary conditions, corresponding to the so-called ordinary surface universality class on both confining boundaries. The general scaling properties for the linear response and correlation functions and for dynamic Casimir forces are discussed. Within the Gaussian approximation we determine the analytic expressions for the associated universal scaling functions and study quantitatively in detail their qualitative features as well as their various limiting behaviors close to the bulk critical point. In addition we consider the effects of time-dependent fields on the fluctuation-induced dynamic Casimir force and determine analytically the corresponding universal scaling functions and their asymptotic behaviors for two specific instances of instantaneous perturbations. The universal aspects of nonlinear relaxation from an initially ordered state are also discussed emphasizing the different crossovers occurring during this evolution. The model considered is relevant to the critical dynamics of actual uniaxial ferromagnetic films with symmetry-preserving conditions at the confining surfaces and for Monte Carlo simulations of spin system with Glauber dynamics and free boundary conditions.     

Morphological Characteristics of Composite Films

For the testing of methods for morphological analysis of composite films, a computer experiment was suggested. Two models were prepared to study the possibility of at least partial reconstruction of 3D structures from their 2D projections or sections. The importance of some morphological characteristics for the reconstruction of size and/or spatial distribution of objects is shown in the paper. It illustrates the usage and significance of the integral transform method for the unfolding of the structures, too.     

Topological Vortices in Superfluid Films

We study the topological structure of the vortex system in a superfluid film. Explicit expressions for the vortex density and velocity field as functions of the superfluid order parameter are derived. The evolution of vortices is also studied from the topological properties of the superfluid order parameter field.     

自持金刚石厚膜上沉积生长ZnO薄膜及发光特性

采用磁控溅射在自持CVD金刚石厚膜的成核面上制备了ZnO薄膜,并实验研究了其生长特性和发光特性随O2和Ar流量的变化。利用X射线衍射(XRD)、光致发光(PL)光谱、电子探针(EPMA)和霍尔测量对样品进行了检测。结果表明,在O2/Ar比值约为1时沉积得到的ZnO薄膜取向较一致,呈现高阻的状态并且发光性能最好。     

Topological Vortices in Superfluid Films

We study the topological structure of the vortex system in a superfiuid film. Explicit expressions for the vortex density and velocity field as functions of the superfluid order parameter are derived. The evolution of vortices is also studied from the topological properties of the superfluid order parameter field.     

飞秒激光器的相位薄膜

论述了飞秒激光器的相位补偿特点，讨论了采用位薄膜作为补偿晶体的色散和相位自调制的飞秒激光器，并对相位薄膜进行了理论设计。     

P-Type Nitrogen-Doped ZnO Films Prepared by In-Situ Thermal Oxidation of Zn_3N_2 Films

P-type nitrogen-doped ZnO films are prepared successfully by in-situ thermal oxidation of Zn_3N_2 films.The prepared films are characterized by x-ray diffraction,non-Rutherford backscattering(non-RBS) spectroscopy,xray photoelectron spectroscopy,and photoluminescence spectrum.The results show that the Zn_3N_2 films start to transform to ZnO at 400°C and the total nitrogen content decreases with the increasing annealing temperature.The p-type films are achieved at 500℃ with a low resistivity of 6.33Ω·cm and a high hole concentration of+8.82 × 10~(17) cm~(-3),as well as a low level of carbon contamination,indicating that the substitutional nitrogen(N_O) is an effective acceptor in the ZnO:N film.The photoluminescence spectra show clear UV emissions and also indicate the presence of oxygen vacancy(V_O) defects in the ZnO:N films.The p-type doping mechanism is briefly discussed.     

Field Emission Properties of Ball-Like Nano-Carbon Thin Films Deposited on Mo Films with Accidented Topography

Ball-like nano-earbon thin films （BNCTs） are grown on Mo layers by microwave plasma chemical vapour deposition （MPCVD） system. The Mo layers are deposited on ceramic substrates by electron beam deposition method and are pretreated by ultrasonically scratching. The optimization effects of ultrasonically scratching pretreatment on the surface micro-structures of carbon films are studied. It is found from field-emission scanning electron microscope （FE-SEM） images and Raman spectra that the surface structures of the carbon films deposited on Mo pretreated are improved, which are composed of highly uniform nano-structured carbon balls with considerable disorder structures. Field emission （FE） measurements are carried out using a diode structure. The experimental results indicate that the BNCTs exhibit good FE properties, which have the turn on field of 1.56 V/μm, and the current density of 1.0mA/cm^2 at electric field of 4.0 V/μm, the uniformly distributed emission site density from a broad well-proportioned emission area of 4 cm^2 are also obtained. Linearity is observed in Fowler Nordheim （F N） plots in higher field region, and the possible emission mechanism of BNCTs is discussed.     

Magnetization of Co-Fe-Ta-B-O Amorphous Thin Films

An amorphous magnetic material system(Co_(20)Fe_(47)Ta_(20)B_(13))_(1-x)O_x is fabricated by magneto sputtering. Three stages of magnetization behavior exist when oxygen content changes in the system. As the oxygen increases, the absence of percolation effect of magnetic nano-particles makes the multi-domain structure broken so that high coercivity appears in the samples with proper oxygen content. A temperature-dependent Stoner–Wohlfarth model is used to explain the magnetization properties at relatively high temperature. Magnetizations with magnetic field in and out of the sample plane are also investigated to prove the mechanisms. This work provides a systematic study of a new kind ofv amorphous magnetic system and is helpful for us to know more about this type of material.     

High-Temperature Electron-Hole Liquid in Diamond Films

Russian Physics Journal -     

聚酰亚胺薄膜的电致发光和光致发光

测量了氙灯辐照后聚酰亚胺(PI)薄膜的光致发光(PL)强度、PL谱和氙灯辐照后直流高电场下PI薄膜的电致发光(EL)强度、EL谱、XRD谱和吸收光谱,研究了其EL、PL特性与微观结构的关系.结果表明:PI薄膜的PL强度随测量时间呈指数衰减,EL强度随场强呈指数增长;辐照39 h后,PI的预击穿场强为2.56MV/cm,...