基于大晶粒MA0.7FA0.3PbI3的薄膜光探测器

为了研究大晶粒高质量钙钛矿薄膜对光探测器的影响,制备了晶粒尺寸超过2 μm的MA_0.7FA_0.3PbI₃薄膜,并基于该薄膜制备了光电导型的光探测器（MCP-PD）。基于该薄膜的光探测器在532 nm和3 V偏置电压下获得了高响应度（0.905 A/W）和探测度（3.18×10¹² Jones）。在相似性能条件下,基于大晶粒尺寸薄膜制备的MCP-PD还表现出较快的响应速度。实验结果表明,大晶粒尺寸的薄膜降低了晶界对载流子传输的阻碍,提升了光探测器的响应度、探测度及响应速度。     

单价银离子在 CaO-P2O5 系统玻璃中的发光特性

在弱还原气氛下制备了单价银离子(Ag⁺)掺杂的CaO-P₂O₅系统玻璃,测试了其在室温下的吸收光谱、激发光谱和发射光谱。Ag⁺-CaO-P₂O₅玻璃的吸收光谱表明两个吸收峰。高能峰位于220nm波长,由4d¹⁰→4d⁹5P¹跃迁引起,低能峰中心位于240nm波长,归因于4d¹⁰→4d⁹5s¹跃迁,该吸收与其发射特性有关。紫外波段的宽带吸收产生了可见波段强烈的荧光发射,发光峰位于440nm波长,半宽度为130nm.研究了掺质浓度与发光特性的关系,随着掺质浓度的增加(0.05～0.25mol%),发光峰向较长波段移动。在Ag₂O含量为0.5mol%时,出现了浓度猝灭现象。为了比较起见,同时还研制了Cu⁺-CaO-P₂O₅及Cu⁺-Ag⁺-CaO-P₂O₅玻璃。     

红外D2喇曼激光器的实验研究

用高功率TEA CO₂激光TEM₀₀模泵浦低温多程池中的D₂,利用其受激转动Raman散射(SRRS),我们获得了11～14μm光谱范围内可调谐Raman激光输出。典型的TEA CO₂ 10R(20)线30MW输入泵浦可获得大约7.93MW的12.5μm红外激光输出。     

高压H2的受激拉曼散射

本文介绍了以高压H₂为工作物质,以倍频的YAG的0.532μm输出为泵浦源的受激拉曼散射实验,实现了总转换效率大于65%的目前最佳输出,得到了从紫外AS₆228.8nm到红外S₄级的4.6μm转换,扩展了脉冲染料激光器的波段,为开展从紫外到红外的光谱工作提供了理想的光频转换器件。     

X2O3(X=B、Al、Ga)-K2O(ZnO)-Nb2O5系统玻璃生成及性质

用通常的玻璃熔融浇注或高温水淬火方法,研究了(B、Al、Ga)₂O₃-K₂O(ZnO)一Nb₂O₅系统玻璃生成能力。测定了有关玻璃的折射率、色散、密度及红外透过率等性质。实验结果表明:钾铌酸盐K(NbO₃)比锌铌酸盐Zn₂(Nb₂O₇)易形成玻璃;X₂O₃-K₂O-Nb₂O₅各系统均能形成玻璃。值得注意的是,X₂O₃含量低于30%mol(甚至可低达10%mol)时,仍然能生成玻璃。这时,Nb₂O₅含量按B³⁺、Al³⁺、Ga³⁺顺序而趋向增加(25-45%mol)。其中Al₂O₂和Ga₂O₃钾铌酸盐玻璃红外透过截止波长大于6μm;Nb₂O₅-B₂O₃-K₂O系统玻璃具有高色散、低折射率等性质,它们的密度与光性相近的其它玻璃相比又比较小。最后,根据玻璃结构参数、键参数、电负性与平均离子半径比的关系等计算结果,推断了Nb⁵⁺的配位数为四和六。Nb₂O₅在Nb₂O₅-X₂O₃-K₂O系统中赋存状态为偏铌酸盐。     

B2O3—La2O3—BaO—Nb2O5系统的玻璃生成范围及其性质

本文研究了在B₂O₃-La₂O₃-BaO-Nb₂O₅四元系统中当B₂O₃含量分别为25、30、35wt%时,该系统的玻璃生成范围和它们的光性、密度等变化规律。结果表明,随着B₂O₃含量的增加,系统的玻璃生成范围向贫Nb₂O₅边界扩充,富Nb₂O₅边表现收缩。工作中得出了该系统分别以SiO₂代B₂O₃、Al₂O₃代BaO后的析晶、折射率、色散及密度等性质的变化规律。最后应用该系统研制定型了713/538玻璃。     

纳米半导体复合薄膜的非线性光学性质及其在激光器中的应用

采用射频磁控溅射技术制备了Ge掺二氧化硅（Ge-SiO₂）和Ge,Al共掺二氧化硅（Ge/Al-SiO₂）两种复合薄膜,并进行了热退火处理形成了纳米Ge镶嵌结构。通过紫外-可见吸收谱测量,确定了两种薄膜中纳米Ge的光学带隙,并采用皮秒激光Z-扫描技术研究了薄膜的非线性光学性质。测试结果显示,在1 064 nm激发下得到的Ge-SiO₂和Ge/Al-SiO₂薄膜的非线性吸收系数分别为-1.23×10^-7 m/V和4.35×10^-8 m/W,前者为饱和吸收,而后者为双光子吸收。把两种薄膜作为可饱和吸收体均可实现1.06 μm激光的被动调Q和被动锁模运转。与Ge-SiO₂薄膜比较,采用Ge/Al-SiO2薄膜可以获得较窄的调Q脉冲和锁模脉冲。最后,理论分析和实验比较了两种薄膜实现被动调Q和锁模的机理。     

S2分子的激发态与X3Σ-g→B3Σ-u吸收谱研究

S₂分子是一种在能源和激光领域有应用前景的物质,几十年来,人们对S₂分子的电子结构与光谱的研究不断深入。应用量子化学从头算方法(完全活性空间多组态自洽场方法和多参考二阶微扰方法)计算了S₂分子的11个电子态,并与其他文献结果作了比较,得到了与其他文献符合较好的结果;讨论了不同方法对激发态计算的适用性的问题:完全活性空间多组态自洽场方法适用于分子平衡态几何构形的优化,考虑到电子的动力学相关,能量的计算多参考二阶微扰方法更好。计算了S₂分子X³Σ^-_g(v)→B³Σ^-_u的垂直吸收谱,给出了速度规范下基态电子态各振动级X³Σ^-_g(v)垂直跃迁到B³Σ^-_u的振子强度,结果表明S₂分子是一种泵浦范围较宽(350~600 nm)的良好的激光工作物质。     

68.5 W连续输出1 060 nm波段半导体激光列阵模块

利用InGaAs/InGaAsP应变量子阱外延层材料制作出高功率半导体激光列阵模块。激光芯片宽1 cm,腔长1200 μm,条宽200 μm,填充密度为50%,前后腔面光学膜分别为单层Al₂O₃和Al₂O₃/5(HfO₂/SiO₂)/HfO₂,室温连续输出功率达到68.5 W,器件光谱中心波长为1 059 nm,光谱宽度(FWHM)为9 nm。     

阿达马光谱术中的数据处理方法—快速阿达马变换

本文系统的讨论了应用于阿达马光谱术中的数据处理方法——快速阿达马变换。给出了:1.阿达马矩阵的构造方法。2.阿达马光谱术中矢量方程的建立。3.置换π₁,π₂的构造。4.判别任意2ⁿ（n≥o）阶阿达马矩阵中任意元素H_μj的判别式的给出:H_μj=(-1)^{μ_n-1j_n-1+μ_n-2j_n-2+…+μ₁j₁+μ₀j₀}。5.快速阿达马变换算式的建立。6.快速阿达马算法的验证。     

The evaluation of surface topography changes in nanoscaled 2,6‐diphenyl anthracene thin films by atomic force microscopy

The physical properties of electronic devices made by 2,6‐diphenyl anthracene (DPA) are influenced by the microtexture of DPA surfaces. This work focused on the experimental investigation of the 3‐D surface microtexture of DPA thin films deposited on OTS (octadecyltrichlorosilane), HMDS (Hexamethyldisilasane), OTMS (octadecyltrimethoxysilane), and Si/SiO₂ (300 nm SiO₂ thickness) substrates with 5 and 50 nm thicknesses and 5 and 10 μm scan size. The thin film surfaces were recorded using atomic force microscopy (AFM) and their images were stereometrically analyzed to obtain statistical parameters, in accordance with ASME B46.1‐2009 and ISO 25178‐2: 2012. The results showed the effect of different manufacturing parameters on microtexture values where the granular structure is confirmed in all films. In addition, root mean square is increased by increasing the thickness from 5 to 50 nm for all types of substrates.     

Precise measurements of nanostructure parameters

The precision of measurements performed by atomic-force microscopy (AFM) and high-resolution electron microscopy (HREM) for solving problems of metrology and diagnostics of solid nanostructures is discussed. The HREM-measured height of a monatomic step on a Si(111) surface covered by a thin natural oxide film is demonstrated to be 0.314 ± 0.001 nm. The same accuracy is ensured by AFM measurements through controlling the Si surface relief with heating in ultra-high vacuum on specially created test objects with the distance between the steps being approximately 2 μm. It is shown that the geometric phase method can be used to quantify the strains in the crystal lattice of strained heterostructures on the basis of HREM images with accuracy to 10⁻⁴%, and in situ irradiation by electrons in HREM measurements can be used to visualize ordered clusterization of vacancies and self-interstitial atoms in {113} planes in Si samples.     

SEM and AFM studies of dip‐coated CuO nanofilms

Cupric oxide (CuO) semiconducting thin films were prepared at various copper sulfate concentrations by dip coating. The copper sulfate concentration was varied to yield films of thicknesses in the range of 445–685 nm by surface profilometer. X‐ray diffraction patterns revealed that the deposited films were polycrystalline in nature with monoclinic structure of (?111) plane. The surface morphology and topography of monoclinic‐phase CuO thin films were examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Surface roughness profile was plotted using WSxM software and the estimated surface roughness was about ～19.4 nm at 30 mM molar concentration. The nanosheets shaped grains were observed by SEM and AFM studies. The stoichiometric compound formation was observed at 30 mM copper sulfate concentration prepared film by EDX. The indirect band gap energy of CuO films was increased from 1.08 to 1.20 eV with the increase of copper sulfate concentrations. Microsc. Res. Tech., 2013. © 2012 Wiley Periodicals, Inc.     

Specimen‐thickness effects on transmission Kikuchi patterns in the scanning electron microscope

We report the effects of varying specimen thickness on the generation of transmission Kikuchi patterns in the scanning electron microscope. Diffraction patterns sufficient for automated indexing were observed from films spanning nearly three orders of magnitude in thickness in several materials, from 5 nm of hafnium dioxide to 3 μm of aluminum, corresponding to a mass‐thickness range of ～5 to 810 μg cm^–2. The scattering events that are most likely to be detected in transmission are shown to be very near the exit surface of the films. The energies, spatial distribution and trajectories of the electrons that are transmitted through the film and are collected by the detector are predicted using Monte Carlo simulations.     

Electrostatic force microscopy study on the domain switching properties of the Pb(Zr0.2Ti0.8)O3 thin films with different crystallographic orientations for the probe-based data storage

The domain switching properties of the ferroelectric Pb(Zr(0.2)Ti(0.8))O(3) (PZT) thin films with two types of crystallographic orientations were investigated by electrostatic force microscopy (EFM). The crystallographic orientations of the PZT thin films were random on the (111)Pt/MgO(100) and c-axis preferred on the (100)Pt/MgO(100), respectively. When dc bias was applied to the films for writing in micro-scale area, electrostatic force images showed that the domain switching was hard in the PZT thin films with random orientation, while the pattern could clearly be written in the PZT films with c-axis orientation. The differences in the domain switching properties of each PZT thin film were investigated in the crystallographic orientations point of view, and the domain switching dynamics were also measured by investigating the nano-sized dot switching behavior with respect to the width of the applied voltage pulse.     

Dependence of surface morphology on molecular structure and its influence on the properties of OLEDs

Most organic light-emitting diodes (OLEDs) have a multilayer structure composed of organic layers such as a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL) and an electron injection layer (EIL) sandwiched between two electrodes. The organic layers are thin solid films with a thickness from a few nano meters to a few tenths nano meter, respectively. Surface morphology of an organic thin solid film in OLEDs depends on the molecular structure of the organic material and has an affect on device performance. To analyze the effect of surface morphology of an organic thin solid film on fluorescence and electroluminescence (EL) properties, thin solid films of 4-(dicyanomethylene)-2-methyl-6-(julolidin-4-yl-vinyl)-4H-pyran (DCM2) and new red fluorophores, (2E,2′E)-3,3′-[4,4″-bis(dimethylamino)-1,1′:4′,1″-terphenyl-2′,5′-diyl]bis[2-(2-thienyl)acrylonitrile] (ABCV-Th) and (2Z,2′Z)-3,3′-[4,4″-bis(dimethylamino)-1,1′:4′,1″-terphenyl-2′,5′-diyl]bis(2-phenylacrylonitrile) (ABCV-P) were investigated by atomic force microscopy (AFM). The samples for EL and AFM measurement were fabricated by the high-vacuum thermal deposition (8×10⁻⁷ Torr) of organic materials onto the surface of indium tin oxide (ITO)-coated glass substrate, in which the layer structures of samples for AFM measurement and those for EL measurement were ITO/NPB (40 nm)/red emitters (80 nm) and ITO/NPB (40 nm)/red emitters (80 nm)/BCP (30 nm)/Liq (2 nm)/Al (100 nm), respectively. The analysis based on AFM measurements well supported that the photoluminescence properties and the device performance were very much dependent upon surface morphology of an organic thin layer.     

Friction, wear and N2-lubrication of carbon nitride coatings: a review

Recent results of tribological properties of carbon nitride (CN_x) coatings are reviewed. CN_x coatings of 100 nm thickness were formed on Si-wafer and Si₃N₄ disks by the ion beam mixing method. Friction and wear tests were carried out against Si₃N₄ balls in the environments of vacuum, Ar, N₂, CO₂, O₂ or air by a ball-on-disk tribo-tester in the load range of 80-750 mN and in the velocity range of 4-400 mm/s.It was found that friction coefficient μ is high (μ=0.2-0.4) in air and O₂, and low (μ=0.01-0.1) in N₂, CO₂ and vacuum. The lowest friction coefficient (μ<0.01) was obtained in N₂. It was also found that N₂ gas blown to the sliding surfaces in air effectively reduced the friction coefficient down to μ≈0.017. Wear rate of CN_x coatings varied in the range 10⁻⁹-10⁻⁵ mm³/N m depending on the environment.The wear mechanisms of CN_x in the nanometer scale were studied by abrasive sliding of an AFM diamond pin in air. It was confirmed that the major wear mechanism of CN_x in abrasive friction was low-cycle fatigue which generated thin flaky wear particles of nanometre size.     

紫外-真空紫外波段的Al+MgF2膜

Al+MgF₂膜是真空紫外波段常用的一种反射膜。根据薄膜光学的电磁场理论计算了正入射条件下Al+MgF₂膜在真空紫外波段的反射率随氟化镁膜厚度的变化规律。研究了Al+MgF₂膜的制备工艺,利用Seya-Namioka紫外-真空紫外反射率计测得Al+MgF₂膜的反射率在150nm～340nm的波段上高于80%。Al+MgF₂膜制备一年后,其真空紫外波段的反射率未有明显变化。     

Pressure drop measurement in microfluidics channel by the Fabry-Perot diaphragm-based flow sensor

The measurement and control of pressure is an important parameter in optimizing flow rates in microfluidic channels. In this paper, we present simulation and experimental results of measuring pressure drop in a rectangular microfluidics channel by two Fabry-Perot (FP) flow sensors. Sensors include two circular diaphragms made of PDMS (Polydimethylsiloxane) with 50 μm thickness and 200 μm radius, located 2 cm apart which the surface of them create FP cavity with end surface of the fiber optic. Fabry-Pérot interferometers above two diaphragms measure the different deflections of the diaphragms caused by pressure changes in the micro channel. The fluid-structure interaction method is used to solve three-dimensional (3D) Navier-Stokes and continuity equations for selecting appropriate diaphragm thickness and validating experimental results. The experimental and theoretical results are in good agreement and according to the experimental results, these sensors have sensitivities of 30 (nm. (μL/min)^-1) and 10 (nm. (μL/min)^-1) without hysteresis and the resolution of the sensor is 33 nL/min.     

Electrostatic force microscopy study on the domain switching properties of the Pb(Zr0.2Ti0.8)O3 thin films with different crystallographic orientations for the probe-based data storage

The domain switching properties of the ferroelectric Pb(Zr_0.2Ti_0.8)O₃ (PZT) thin films with two types of crystallographic orientations were investigated by electrostatic force microscopy (EFM). The crystallographic orientations of the PZT thin films were random on the (1 1 1)Pt/MgO(1 0 0) and c-axis preferred on the (1 0 0)Pt/MgO(1 0 0), respectively. When dc bias was applied to the films for writing in micro-scale area, electrostatic force images showed that the domain switching was hard in the PZT thin films with random orientation, while the pattern could clearly be written in the PZT films with c-axis orientation. The differences in the domain switching properties of each PZT thin film were investigated in the crystallographic orientations point of view, and the domain switching dynamics were also measured by investigating the nano-sized dot switching behavior with respect to the width of the applied voltage pulse.