劳伦斯伯克利国家实验室的先进光源，进行了实验在化学动力学光束线和科学办公室基础能源科学办公室，美国能源部根据合同号DE-AC02-05CH11231支持，通过化学科学部。

1。样品装载<ol><li>删除后法兰，拆卸3/8“的不锈钢喷嘴管从设备（参见图1和图2），并确保它是干净和100毫米的孔是明确的（这可以通过寻找光源，通过它）。〜1毫升乙醇清洗，填充管，用棉花提示擦洗内。另外，在超声波浴中充满了肥皂和水或乙醇约20分钟，然后将喷嘴干燥的压缩空气。 </li><li>使用一个小的，干净的抹刀，地点约250mg样品在所述喷嘴的前部，靠近该孔，但不阻止它。避免孔被阻塞的一个好方法是将一个小球铝箔或玻璃纤维在前面的小孔，然后加入样品粉末。采用棉花前端推到管中的样品，以确保它是在前面的25毫米的管。这将包括前部的加热区。 </li><li>重新装上喷嘴仔细的装置里面，以避免移动样品粉末。然后附上鸟笼适配器（参见图2），加热块和热电偶（参见图3）。 </li><li>关闭真空室之前，测量从凸缘表面的距离为22.5英寸的喷嘴的前端，这将允许0.5英寸之间的喷嘴和锥孔。 </li><li>当真空室是封闭的，测试的加热器筒和热电偶连接，以确保它们连接到馈通连接器。 </li><li>确保载气入口阀被关闭。 </li><li>关闭排气阀（如果使用）。 </li><li>慢慢开始泵送使用粗加工泵（4阀）的腔室，腔室中的压力时，&lt;1乇，从涡轮分子泵（5台泵）。 </li><li>当腔室中的压力是10 -6乇时，应用的电压的离子光学飞行质谱仪，和微通道板检测器（后者上的电压逐渐应当接通）（参见图1，用于各种电压）的时间。 </li><li>打开的VUV快门，以便在腔室的光子束。 </li><li>打开的载体气体入口阀和背压调节器设置到第460（这是一个真空调节器，因此，当设置到第460行中的压力将调节至300乇，测量在负的范围从0到-760乇） 。 </li><li>在这些条件下的源和质谱仪室的中的压力应为〜1×10 -6乇〜1×10 -6乇，分别。 </li></ol> 2。收购的质谱<ol><li>百兆网卡（型号为P7889，100 PS / BIN）软件在电脑上，让它在后台运行。 </li><li>打开Labview数据采集程序：“一般Interface.vi”（ 图4）。 </li></ol><html> （*此软件和其它的LabVIEW代码在光束线和相应的作者没有成本提供给大家分享） <ol start="3"><li>在LabVIEW软件使用ALS控制“选项卡 ，设置到所需波长的光子能量。 </li><li>在定标器“选项卡上，设置的时间单位数一起被离散化 （一般为32），的范围内 （箱数）和扫描 （质谱数由彼此的顶部上，以形成最终的质谱），然后单击“ 接受”，因此，这些值将被存储和使用。 </li><li>接下来，单击“开始数据采集得到的数据 。当收购结束后，质谱会出现在屏幕上。 </li><li>通过点击“ 保存 ”按钮，保存的质谱。 （在100 ps的单位所获得的频谱的X轴对应于离子的飞行时间） </li></ol>TLE“&gt; 3。收购的光电离效率曲线（PIE） <ol><li>在LabVIEW软件使用“ALS扫描 ”选项卡（ 图5），它是有可能获得数据而调整光束线电机。在这种情况下，选择电机的“ 单声道T3能源”的调整在不同的光子能量（波荡器内的同步会自动移动到所需的波长相匹配）。光子的能量设置为所需的值（单位：eV）。 </li><li>输入启动和停止的能量（EV）以及步长。 </li><li>不要输入扫描次数 - 这将是自动更新您输入的值在步骤2.4。 </li><li>单击“ 阅读，从K486读通过光电二极管的光电流测量。 </li><li>接下来，单击“ 开始 ”开始扫描。系统将提示您选择一个文件名的数据将被存储在运行结束。 </li><li>第一列中的数据文件都TAIN的bin的数量（豳＃）和需要转换为质量单位13。典型值是：质量= 0.6 + 1xE-3（豳＃）+ 5xE-7（豳＃）^ 2（更精确的质量校准可以通过使用一个已知的混合气体或室内空气即主要是O 2，N 2和H 2 O的混合物，并符合他们的到来，二次多项式） </li><li>保存数据文件转换成质量与第一列。 </li><li>要绘制PIE曲线，一个简单的方法是使用第二个称为的的“ALS能源scan.vi”，其目的是分析扫描数据，并生成PIE的Labview程序。 </li></ol> 4。绘制一个光电离效率曲线（PIE） <ol><li>正如上面的分析可以完成使用“ALS能源scan.vi”程序（参见图6），然而，我们也将在这里描述到的数据进行分析，而它所需的步骤。 </li><li>在启动程序时，系统会提示您选择的文件containin的克的数据。这是文件保存在步骤3.7，并包含在不同的光子能量在下一列中的第一列和离子计数的群众。请注意，在该文件中的第一行和第二行表示光子能量和该列中的数据的光电流，分别。 </li><li>顶部面板中的存在是一个二维的数据曲线;移动红色水平标记选择一个在一个特定的被显示在下部面板的光子能量的质谱。 </li><li>接下来的步骤是集成的特定质量的离子计数中减去背景信号，同时，在每个光子能量。应设置在下部面板的两个垂直的红色标记以集成的质量峰的周围而没有数据可以作为背景值附近的一个区域与周围的两个蓝色标记。该软件将出现在右边的面板中减去背景的综合数据。 </li><li>介绍一个真实的PIE曲线必须纠正的离子数，以不同的光子通量一个吨的每一步。这是自动完成由软件实现。如果您选择跳过此更正，请单击“关闭” 电流校正“按钮的右侧面板的顶部。如果您选择手动做到这一步，每个光子的能量的光电二极管的量子效率，必须考虑到（从光电二极管制造商，并通过相应的作者），见式（1）。否则，这是所有自动完成的软件。 </li></ol><img alt="式（1）" fo:src="/files/ftp_upload/50164/50164eq1highres.jpg" src="/files/ftp_upload/50164/50164eq1.jpg" /><ol start="6"><li>在右下角点击保存频谱保存校正后的PIE曲线。 </li></ol>

<ol>
	<li>Golan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ionization+of+dimethyluracil+dimers+leads+to+facile+proton+transfer+in+the+absence+of+hydrogen+bonds.">Ionization of dimethyluracil dimers leads to facile proton transfer in the absence of hydrogen bonds.</a> Nat. Chem. 4, 323-329 (2012).</li><li>Belau, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vacuum-Ultraviolet+Photoionization+Studies+of+the+Microhydration+of+DNA+Bases+(Guanine,+Cytosine,+Adenine,+and+Thymine).">Vacuum-Ultraviolet Photoionization Studies of the Microhydration of DNA Bases (Guanine, Cytosine, Adenine, and Thymine).</a> The Journal of Physical Chemistry A. 111, 7562-7568 (2007).</li><li>Golan, A., Ahmed, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ionization+of+Water+Clusters+Mediated+by+Exciton+Energy+Transfer+from+Argon+Clusters.">Ionization of Water Clusters Mediated by Exciton Energy Transfer from Argon Clusters.</a> The Journal of Physical Chemistry Letters. 3, 458-462 (2012).</li><li>Nicolas, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vacuum+Ultraviolet+Photoionization+of+C3.">Vacuum Ultraviolet Photoionization of C3.</a> Journal of the American Chemical Society. 128, 220-226 (2005).</li><li>Kamarchik, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectroscopic+signatures+of+proton+transfer+dynamics+in+the+water+dimer+cation.">Spectroscopic signatures of proton transfer dynamics in the water dimer cation.</a> Journal of Chemical Physics. 132, (2010).</li><li>Khistyaev, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+microhydration+on+ionization+energies+of+thymine.">The effect of microhydration on ionization energies of thymine.</a> Faraday Discussions. 150, 313-330 (2011).</li><li>Bravaya, K. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+pi-stacking,+H-bonding,+and+electrostatic+interactions+on+the+ionization+energies+of+nucleic+acid+bases:+adenine-adenine,+thymine-thymine+and+adenine-thymine+dimers.">The effect of pi-stacking, H-bonding, and electrostatic interactions on the ionization energies of nucleic acid bases: adenine-adenine, thymine-thymine and adenine-thymine dimers.</a> Physical Chemistry Chemical Physics. 12, 2292-2307 (2010).</li><li>Kostko, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ionization+of+cytosine+monomer+and+dimer+studied+by+VUV+photoionization+and+electronic+structure+calculations.">Ionization of cytosine monomer and dimer studied by VUV photoionization and electronic structure calculations.</a> Physical Chemistry Chemical Physics. 12, 2860-2872 (2010).</li><li>Bravaya, K. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electronic+Structure+and+Spectroscopy+of+Nucleic+Acid+Bases:+Ionization+Energies,+Ionization-Induced+Structural+Changes,+and+Photoelectron+Spectra.">Electronic Structure and Spectroscopy of Nucleic Acid Bases: Ionization Energies, Ionization-Induced Structural Changes, and Photoelectron Spectra.</a> Journal of Physical Chemistry A. 114, 12305-12317 (2010).</li><li>Leone, S. R., Ahmed, M., Wilson, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+dynamics,+molecular+energetics,+and+kinetics+at+the+synchrotron.">Chemical dynamics, molecular energetics, and kinetics at the synchrotron.</a> Physical Chemistry Chemical Physics. 12, 6564-6578 (2010).</li><li>Scoles, G., Bassi, D., Buck, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Atomic and Molecular Beam Methods. 1, (1988).</li><li>Pauly, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Atom, Molecule and Cluster Beams I. , (2000).</li><li>Wiley, W. C., McLaren, I. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-of-Flight+Mass+Spectrometer+with+Improved+Resolution.">Time-of-Flight Mass Spectrometer with Improved Resolution.</a> Review of Scientific Instruments. 26, 1150-1157 (1955).</li><li>Levy, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Spectroscopy+of+Very+Cold+Gases.">The Spectroscopy of Very Cold Gases.</a> Science. 214, 263-269 (1981).</li></ol>

在超音速喷流产生的分子束的膨胀所产生的单体和二聚体。的DNA碱基的少量样品被放置在一个热蒸发源和加热以产生足够的蒸气压。氩气进行蒸气通过100微米口，通过2毫米的分离器，产生冷分子束14。可替换地，一个热情洋溢束源可以使用，其中样本被放置在与质谱仪的推斥极板（离子光学元件）连接到加热的烘箱。 我们使用真空紫外灯（7.4-25 eV）的，轻轻电离分子...

<table border="1"&gt;<tr&gt;<td<strong&gt;试剂/材料的名称</strong</td&gt;<td<strong&gt;公司</strong</td&gt;<td<strong&gt;产品目录号</strong</td&gt;<td<strong&gt;评论</strong</td&gt;</tr&gt;<tr&gt;<td&gt;尿嘧啶</td&gt;<td&gt; SIGMA</td&gt;<td&gt; U0750</td&gt;<td</td&gt;</tr&gt;<tr&gt;<td&gt; 1,3 - 二甲基脲嘧啶</td&gt;<td&gt;爱秩序</td&gt;<td&gt; 349801</td&gt;<td</td&gt;</tr&gt;</table

molecular beam mass spectrometry with tunable vacuum ultraviolet (vuv) synchrotron radiation

可调的软电离质谱耦合是一个功能强大的方法来研究孤立的分子复合物和集群及其光谱学和动力学1-4。生物分子的光电离过程的基础研究提供这些系统的电子结构有关的信息。此外，电离能和其他的生物分子在气相中的测定是不平凡的，这些实验提供了一个平台，产生这些数据。我们已经开发出一种汽化热技术加上超音速分子束，它提供一种温和的方式输送到气相中的这些物种。明智地的源气体和温度的组合允许用于形成二聚体和较高的DNA碱基簇。这个特定的工作的重点是， 即非共价相互作用，氢键，堆叠，和静电相互作用的影响，上的电离能和个体的生物分子，它们的配合，在微水1，5-9水化的质子转移。 我们已经进行了理论和实验的可视化特性的光电离动力学的气相尿嘧啶和1,3 -二甲基脲嘧啶二聚体，再加上分子束同步辐射化学动态学光束线的先进光源位于10和实验细节这里。这让我们观察1,3 -二甲基脲嘧啶二聚体内的质子传递，系统与π堆叠的几何形状和没有氢键1。分子束提供了一个非常方便和有效的方式来隔离环境扰动的回报可以准确的比较与电子结构计算，11，12样品的兴趣。通过调节光子的能量同步辐射光电离效率（PIE）曲线可以绘制告诉我们的阳离子电子态。然后这些值可以进行比较的理论模型和计算方法，反过来，详细解释了调查的种类1，3，电子结构和动力学。

图7示出了典型的质谱超音速膨胀的（A）的1,3 -二甲基尿嘧啶蒸气和PIE曲线的三个主要功能（在m / z 140的单体，在M / Z = 141的质子化的单体，和1的在M / Z 280）-1,3 - 二甲基脲嘧啶二聚体之间的真空紫外扫描摘录自8 eV和10 EV（B）。连续三次扫描，灰色的阴影是标准差。 <img alt="图1" fo:content-width="5in" fo:src="/files/ftp_upload/50164/50164fig1highres.jpg"...

Watch this Scientific Journal Video about Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet VUV Synchrotron Radiation at JoVE.com

Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet VUV Synchrotron Radiation

加上可调谐的真空紫外同步辐射光电离质谱计在分子束提供了一个方便的工具来探索孤立的气相分子和簇的电子结构。 DNA碱基二聚体的质子转移机制，用这种方法鉴定。

可调式真空紫外（VUV）同步辐射分子束质谱分析

Tunable soft ionization coupled to mass spectroscopy is a powerful method to investigate isolated molecules, complexes and clusters and their spectroscopy ...

molecular-beam-mass-spectrometry-with-tunable-vacuum-ultraviolet-vuv

Research

JoVE Journal

Engineering

Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet (VUV) Synchrotron Radiation

12.9K 次观看.  Lawrence Berkeley National Laboratory. 加上可调谐的真空紫外同步辐射光电离质谱计在分子束提供了一个方便的工具来探索孤立的气相分子和簇的电子结构。 DNA碱基二聚体的质子转移机制，用这种方法鉴定。

视频: Molecular Beam Mass Spectrometry With Tunable Vacuum Ultraviolet VUV Synchrotron Radiation

Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries Using Synchrotron Radiation Techniques

Intercalation compounds such as transition metal oxides or phosphates are the most commonly used electrode materials in Li-ion and Na-ion batteries. During insertion or removal of alkali metal ions, the redox states of transition metals in the compounds change and structural transformations such as phase transitions and/or lattice parameter increases or decreases occur. These behaviors in turn determine important characteristics of the batteries such as the potential profiles, rate capabilities, and cycle lives. The extremely bright and tunable x-rays produced by synchrotron radiation allow rapid acquisition of high-resolution data that provide information about these processes. Transformations in the bulk materials, such as phase transitions, can be directly observed using X-ray diffraction (XRD), while X-ray absorption spectroscopy (XAS) gives information about the local electronic and geometric structures (e.g.&#160;changes in redox states and bond lengths). In situ experiments carried out on operating cells are particularly useful because they allow direct correlation between the electrochemical and structural properties of the materials. These experiments are time-consuming and can be challenging to design due to the reactivity and air-sensitivity of the alkali metal anodes used in the half-cell configurations, and/or the possibility of signal interference from other cell components and hardware. For these reasons, it is appropriate to carry out ex situ experiments (e.g.&#160;on electrodes harvested from partially charged or cycled cells) in some cases. Here, we present detailed protocols for the preparation of both ex situ and in situ samples for experiments involving synchrotron radiation and demonstrate how these experiments are done.

We describe the use of synchrotron X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques to probe details of intercalation/deintercalation processes in electrode materials for Li-ion and Na-ion batteries. Both in situ and ex situ experiments are used to understand structural behavior relevant to the operation of devices

正极材料的同步辐射技术锂离子和钠离子电池表征

Intercalation compounds such as transition metal oxides or phosphates are the most commonly used electrode materials in Li-ion and Na-ion batteries. ...

科研

工程学

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Owing to its relativistic low-energy charge carriers, the interaction between graphene and various impurities leads to a wealth of new physics and degrees of freedom to control electronic devices. In particular, the behavior of graphene&#8217;s charge carriers in response to potentials from charged Coulomb impurities is predicted to differ significantly from that of most materials. Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) can provide detailed information on both the spatial and energy dependence of graphene&#39;s electronic structure in the presence of a charged impurity.&#160;The design of a hybrid impurity-graphene device, fabricated using controlled deposition of impurities onto a back-gated graphene surface, has enabled several novel methods for controllably tuning graphene&#8217;s electronic properties.1-8 Electrostatic gating enables control of the charge carrier density in graphene and the ability to reversibly tune the charge2 and/or molecular5 states of an impurity. This paper outlines the process of fabricating a gate-tunable graphene device decorated with individual Coulomb impurities for combined STM/STS studies.2-5 These studies provide valuable insights into the underlying physics, as well as signposts for designing hybrid graphene devices.

This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.

对于扫描隧道显微学与库仑杂质制造门可调谐石墨烯器件

Owing to its relativistic low-energy charge carriers, the interaction between graphene and various impurities leads to a wealth of new physics and degrees ...

Failure Analysis of Batteries Using Synchrotron-based Hard X-ray Microtomography

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent of lithium-ion batteries, researchers have known that the lithium metal anode has the highest theoretical energy density of any anode material. However, rechargeable batteries containing a lithium metal anode are not widely used in consumer products because the growth of lithium dendrites from the anode upon charging of the battery causes premature cell failure by short circuit. Lithium dendrites can also form in commercial lithium-ion batteries with graphite anodes if they are improperly charged. We demonstrate that lithium dendrite growth can be studied using synchrotron-based hard X-ray microtomography. This non-destructive imaging technique allows researchers to study the growth of lithium dendrites, in addition to other morphological changes inside batteries, and subsequently develop methods to extend battery life.

Synchrotron-based hard X-ray microtomography is used to image the electrochemical growth of dendrites from a lithium metal electrode through a solid polymer electrolyte membrane.

电池的使用同步为基础的硬X射线微断层故障分析

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent ...

Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films

The biological uptake of plutonium (Pu) in aquatic ecosystems is of particular concern since it is an alpha-particle emitter with long half-life which can potentially contribute to the exposure of biota and humans. The diffusive gradients in thin films technique is introduced here for in-situ measurements of Pu bioavailability and speciation. A diffusion cell constructed for laboratory experiments with Pu and the newly developed protocol make it possible to simulate the environmental behavior of Pu in model solutions of various chemical compositions. Adjustment of the oxidation states to Pu(IV) and Pu(V) described in this protocol is essential in order to investigate the complex redox chemistry of plutonium in the environment. The calibration of this technique and the results obtained in the laboratory experiments enable to develop a specific DGT device for in-situ Pu measurements in freshwaters. Accelerator-based mass-spectrometry measurements of Pu accumulated by DGTs in a karst spring allowed determining the bioavailability of Pu in a mineral freshwater environment. Application of this protocol for Pu measurements using DGT devices has a large potential to improve our understanding of the speciation and the biological transfer of Pu in aquatic ecosystems.

The technique of diffusive gradients in thin films (DGT) is proposed for speciation studies of plutonium. This protocol describes diffusion experiments probing the behavior of Pu(IV) and Pu(V) in presence of organic matter. DGTs deployed in a karstic spring allow assessment of the bioavailability of Pu.

环境钚的薄膜弥散形态和生物利用度测量

The biological uptake of plutonium (Pu) in aquatic ecosystems is of particular concern since it is an alpha-particle emitter with long half-life which can ...

Seedless Growth of Bismuth Nanowire Array via Vacuum Thermal Evaporation

Here a seedless and template-free technique is demonstrated to scalably grow bismuth nanowires, through thermal evaporation in high vacuum at RT. Conventionally reserved for the fabrication of metal thin films, thermal evaporation deposits bismuth into an array of vertical single crystalline nanowires over a flat thin film of vanadium held at RT, which is freshly deposited by magnetron sputtering or thermal evaporation. By controlling the temperature of the growth substrate the length and width of the nanowires can be tuned over a wide range. Responsible for this novel technique is a previously unknown nanowire growth mechanism that roots in the mild porosity of the vanadium thin film. Infiltrated into the vanadium pores, the bismuth domains (~ 1 nm) carry excessive surface energy that suppresses their melting point and continuously expels them out of the vanadium matrix to form nanowires. This discovery demonstrates the feasibility of scalable vapor phase synthesis of high purity nanomaterials without using any catalysts.

A protocol for seedless and high yield growth of bismuth nanowire arrays through vacuum thermal evaporation technique is presented.

铋纳米线阵列通过真空热蒸发无核增长

Here a seedless and template-free technique is demonstrated to scalably grow bismuth nanowires, through thermal evaporation in high vacuum at RT. ...

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm2, but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample&#39;s properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 &#181;m all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

For this study synchrotron radiation micro-tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron&#39;s high flux and brightness the sample was imaged in just 3 min&#160;with an 8.7 &#181;m spatial resolution.

利用同步辐射微断层调查的多尺度三维微电子封装

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data ...

Plasma-assisted Molecular Beam Epitaxy of N-polar InAlN-barrier High-electron-mobility Transistors

Plasma-assisted molecular beam epitaxy is well suited for the epitaxial growth of III-nitride thin films and heterostructures with smooth, abrupt interfaces required for high-quality high-electron-mobility transistors (HEMTs). A procedure is presented for the growth of N-polar InAlN HEMTs, including wafer preparation and growth of buffer layers, the InAlN barrier layer, AlN and GaN interlayers and the GaN channel. Critical issues at each step of the process are identified, such as avoiding Ga accumulation in the GaN buffer, the role of temperature on InAlN compositional homogeneity, and the use of Ga flux during the AlN interlayer and the interrupt prior to GaN channel growth. Compositionally homogeneous N-polar InAlN thin films are demonstrated with surface root-mean-squared roughness as low as 0.19 nm and InAlN-based HEMT structures are reported having mobility as high as 1,750 cm2/V&#8729;sec for devices with a sheet charge density of 1.7 x 1013 cm-2.

Molecular beam epitaxy is used to grow N-polar InAlN-barrier high-electron-mobility transistors (HEMTs). Control of the wafer preparation, layer growth conditions and epitaxial structure results in smooth, compositionally homogeneous InAlN layers and HEMTs with mobility as high as 1,750 cm2/V&#8729;sec.

N极性InAlN阻高电子迁移率晶体管的等离子体辅助分子束外延

Plasma-assisted molecular beam epitaxy is well suited for the epitaxial growth of III-nitride thin films and heterostructures with smooth, abrupt ...

Focused Ion Beam Fabrication of LiPON-based Solid-state Lithium-ion Nanobatteries for In Situ Testing

Solid-state electrolytes are a promising replacement for current organic liquid electrolytes, enabling higher energy densities and improved safety of lithium-ion (Li-ion) batteries. However, a number of setbacks prevent their integration into commercial devices. The main limiting factor is due to nanoscale phenomena occurring at the electrode/electrolyte interfaces, ultimately leading to degradation of battery operation. These key problems are highly challenging to observe and characterize as these batteries contain multiple buried interfaces. One approach for direct observation of interfacial phenomena in thin film batteries is through the fabrication of electrochemically active nanobatteries by a focused ion beam (FIB). As such, a reliable technique to fabricate nanobatteries was developed and demonstrated in recent work. Herein, a detailed protocol with a step-by-step process is presented to enable the reproduction of this nanobattery fabrication process. In particular, this technique was applied to a thin film battery consisting of LiCoO2/LiPON/a-Si, and has further been previously demonstrated by in situ cycling within a transmission electron microscope.

Focused Ion Beam Fabrication of LiPON-based Solid-state Lithium-ion Nanobatteries for In Situ Testing

A protocol for the fabrication of electrochemically active LiPON-based solid-state lithium-ion nanobatteries using a focused ion beam is presented.

基于 LiPON 的固态锂离子 Nanobatteries 的聚焦离子束制备方法在原位测试中的研究

Solid-state electrolytes are a promising replacement for current organic liquid electrolytes, enabling higher energy densities and improved safety of ...

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.

A protocol for the production of simple structured organic light-emitting diodes (OLEDs) is presented.

真空沉积有机发光二极管的生产与表征

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex ...

Fabrication of Schottky Diodes on Zn-polar BeMgZnO/ZnO Heterostructure Grown by Plasma-assisted Molecular Beam Epitaxy

Heterostructure field effect transistors (HFETs) utilizing a two dimensional electron gas (2DEG) channel have a great potential for high speed device applications. Zinc oxide (ZnO), a semiconductor with a wide bandgap (3.4 eV) and high electron saturation velocity has gained a great deal of attention as an attractive material for high speed devices. Efficient gate modulation, however, requires high-quality Schottky contacts on the barrier layer. In this article, we present our Schottky diode fabrication procedure on Zn-polar BeMgZnO/ZnO heterostructure with high density 2DEG which is achieved through strain modulation and incorporation of a few percent Be into the MgZnO-based barrier during growth by molecular beam epitaxy (MBE). To achieve high crystalline quality, nearly lattice-matched high-resistivity GaN templates grown by metal-organic chemical vapor deposition (MOCVD) are used as the substrate for the subsequent MBE growth of the oxide layers. To obtain the requisite Zn-polarity, careful surface treatment of GaN templates and control over the VI/II ratio during the growth of low temperature ZnO nucleation layer are utilized. Ti/Au electrodes serve as Ohmic contacts, and Ag electrodes deposited on the O2 plasma pretreated BeMgZnO surface are used for Schottky contacts.

Attainment of high-quality Schottky contacts is imperative for achieving efficient gate modulation in heterostructure field effect transistors (HFETs). We present the fabrication methodology and characteristics of Schottky diodes on Zn-polar BeMgZnO/ZnO heterostructures with high-density two dimensional electron gas (2DEG), grown by plasma-assisted molecular beam epitaxy on GaN templates.

等离子体辅助分子束外延法制备的锌极性 BeMgZnO/氧化锌异质结构肖特基二极管的制备

Heterostructure field effect transistors (HFETs) utilizing a two dimensional electron gas (2DEG) channel have a great potential for high speed device ...