作者好心承认从"Akademische GESELLSCHAFT利普施塔特"，以及从"Ministerium献给创新，Wissenschaft与研究部des Landes酒店北威州的"金融支持。照片在图1，图2和5礼貌马库斯HORSTMANN，应用科学哈姆 - 利普施塔特大学。

1.样品制备X射线计算机断层扫描（CT） <ol><li>胶样品（LED 参见材料节）使用热熔粘合剂适当长度的2毫米直径的中空碳纤维条。 </li><li>通过如果需要，用热风枪调整试样位置。使用三爪卡盘固定在CT-样品室中的样品。 </li></ol> 2. CT测量设置<ol><li>根据X射线管的控制软件进行升温和定心程序。 注意:制造商的CT和由供应商（ 参见材料节）指定的标准协议的使用管的控制软件。 </li><li>校准光束，并且使用的数据采集软件，如在材料部分中指定检测器。确定暗电流和调整偏移和根据由制造商（ 参见材料节）提供的标准程序检测器的增益。 </li><li>调整成像PARAMETERS。对于这里显示的效果，请使用以下调整:将图像放大至36.37，设定体素尺寸为1.37微米，图像的设置数量为1800（每360度），设置成像时间为500毫秒，平均图像的设置数量为3和跳帧1，设置的图像大小为2284点¯x2,304像素的数量。 </li><li>调整测量参数。对于所示的结果用下面的调整:将焦点对象的距离（FOD）至5.5毫米，设置焦点检测器的距离（FDD）至200毫米，设置X射线管电压为100千伏和管电流135微安，使用0.2毫米铜箔的束硬化。 </li></ol> 3，CT扫描性能注:X射线强度可以在测量过程中变化。为了补偿这些最终波动，利息率（ROI）窗口的一个区域被放置在X射线不会与样品干扰。该区域不受通过样品的X射线的吸收，因此它是具有最高测量的强度的区域。 <ol><li>通过确定一个完整旋转过程中不受被测物体遮挡的区域选择的投资回报率。在与实时图像，按下测量窗口，按住鼠标左键，并绘制了一个红色的框架窗口。 </li><li>右击该窗口的框架上打开上下文菜单。然后选择" 设置为观察窗口 "。该框架的颜色将变为黄色，而观察窗口将被固定在测量窗口。 注意:使用此软件的功能，因此设置的观察窗，并限定在扫描的图像，其中该X射线不与样品相互作用的区域。这是纠正的光线，这直接击中探测器灰度值的可能漂移（无射线，造成空气的灰度值）。它是样本的完整旋转期间在图像中最亮的区域。 注意:由于该事实，即X射线管的加热将导致管的材料的热膨胀，一个软件模块被激活校正这样的效果。这些效应导致在目标上的X射线焦点偏移，以及在空间上，其中在测量期间将导致所记录的图像所测量的对象的运动。 <ol><li>激活软件模块" 自动扫描优化 "，通过其中9个图像样本的实际扫描之前进行。这些图像拍摄于40℃的步骤，而转动样品。 注:此软件模块将除了热效应的修正也允许样品本身的较小机械运动的校正。模块在测量软件的图形用户界面中。 </li><li>此外激活模块" 探测器移例行程序 "。这两个模块开始实际CT扫描之前， 同时激活确保校正样品的运动和环文物。 注意:这个软件模块用于减少环状伪影:该检测器移动到一个位置约 ±从初始位置10像素和拍摄的所有图像被平均化。这减少了影响故障象素。 </li><li>使用该采集软件的" 自动扫描优化 "和" 检测器移例行程序 "用于上述目的，两个模块可以分别选择，并在此调查同时使用。 </li></ol></li><li>通过启动在采集软件的" 数据采集程序 "扫描样本。 </li></ol> 4.重建卷的信息，微制备规划<ol><li>使用制造商的重建软件渲染卷信息。体绘制进行数字使用计算集群重建由X射线吸收呈现的样品的特性。 </li><li>应用图像校正算法:六六六+（束硬化校正）申请"不同的材料"（这是5.8），以消除束硬化和扫描优化删除不需要的样品运动参见 3.2）的值。进行这些步骤出根据供应商的软件使用手册（ 参见材料部分）。 </li><li>选择用于重建的区域，并定义感兴趣区域（ROI）的区域。在此情况下，ROI是通过其旋转在CT样品室中描述了一整圈时该LED占据的体积限定。利用软件选项" 使用观察 "和" 投资回报率CT-过滤器 "，以抑制文物，坚持供应商的软件使用手册（ 参见材料部分），这样做的时候。 </li><li>对于重建ROI的体积。在重建软件设定的ROI，过滤器和校正选项之后，如由仪器的供应商指定的执行使用计算群集的容积重建（参见材料部分）。 </li><li>转移重建数据来对CT-数据分析软件，在XY对准样品，使用该软件的" 简单的注册 "功能XZ和YZ平面。应用" 中间 "的过滤，使用滤镜尺寸"3"。 注:进如在软件手册中描述了以下步骤（ 参见材料部分）。 <ol><li>使用该软件，检查所呈现量，并为您在设备结构电气互连，以保证光线的顶部发光半导体芯片由焊垫的设备下的电流供应。 </li><li>定义切割位置和样品量被删除通过研磨和抛光为随后的微制剂，如剥离后设备依然运行（免开电路）。使用该软件的距离和测量工具，以确保SPECIM的可操作性烯后微制剂（长度可以由1毫米×1毫米的公知的LED芯片的尺寸进行校准）。 </li></ol></li></ol> 5.微准备<ol><li>焊接银线手动所述LED的阳极和阴极垫。使用直径为1mm，并用该组合物的60％的Sn，39％Pb和1％的Cu焊料丝。确保电线的适当定位。 </li><li>采用透明的支持在环氧树脂中嵌入的LED（ 例如 ，25毫米或40毫米直径环）。钻在载体的相反侧上的两个小孔和饲料银线（其接触LED）通过它。位置通过拧紧或拧松银线对齐LED和支持体的前边缘的装置的LED。 <ol><li>填有硅烧杯内环氧环预处理，以确保它不会粘到环氧和随后让环氧树脂变硬。 </li></ol></li><li>利用体视显微镜，视觉上确保支持和LED对齐。 MECHANICALLý除去任何树脂，其是在过量（ 例如 ，支持体以外），通过用粗砂纸打磨。 </li><li>固定在LED（嵌入在环氧树脂），以平面的方式向样本保持器，用于精密磨削。 </li><li>使用带有磨损的测量研磨机和从目标飞机的位置取出样品表面到100微米。 </li><li>小心使用9微米金刚石悬浮液手动操作的研磨机去除更多的材料。用立体显微镜控制磨损的进展频繁。 </li><li>在到达目标区域，如通过CT扫描的定义，切换至3μm金刚石悬浮液和最终合适的抛光悬浮液，通过改变所使用的手动磨床的相应研磨和抛光盘。控制与立体显微镜在很短的间隔进度。 注:在理想情况下所制备的表面现在将对应于在CT测量所限定的目标平面。 </li><li>在步骤5。5和5.6总是除去研磨和通过用去离子水漂洗并用棉纤维垫擦拭使用显微镜之前抛光悬浮液。 </li><li>抛光后，观察光滑，使用立体显微镜划伤的表面上。清洁，用去离子水和棉纤维垫的试样，并且通过使用吹风机用乙醇（纯甲基化酒精）冲洗并干燥除去水。 </li><li>检查试样用于电的可操作性， 即 ，电流流过发光正向二极管和以相反的方向上没有电流流过，使用数字万用表。 </li></ol> 6. LM测量设置<ol><li>摩标本适当的样品持有人CLEM（ 参见材料部分）。确保样品架固定在LM，溅射镀膜机和扫描电镜使用的样本。 </li><li>调节校准标记（ 在支架的L-结构 ），以相同的高度样品表面（ 约 4毫米&lt;/ STRONG&gt;）。确保该研磨面是平行于LM的焦平面。固定样品架到LM的电动XY阶段。 LED连接到电源。该电源应该恒流模式。 </li><li>通过保存作为参考点的校准标记的位置校准在xy阶段样本保持器的位置。 注:此步骤包括在用户手册中描述半自动过程（ 参见材料部分）的详细说明。 </li></ol> 7. LM表征<ol><li>移动的LM XY阶段使得样品的投资回报率是在视LM的领域。确保LM相机具有通过自动校准精确的白平衡作为LM-软件和使用白色参考表面提供（如纸上）。 </li><li>在的化合物的LM执行LM成像根据由供应商（ 参见材料所提供的用户手册中所述的步骤的反射光secti上）。对于这里示出的结果的明场，暗场和偏振对比度用一个50X物镜成像。 </li><li>开关上的电源和调LED发射。关闭LM照明和调整LM相机（ 约 92毫秒取决于排放强度）的曝光时间。获取样品（发光对比度）内的光分布的LM形象。 </li><li>如果适用，通过激活LM照明和LED同时对比其他图像发光在一起。 注:否则，用不同的对比度的图像也可以通过以后的图像处理的装置进行混合。 </li><li>与在由供应商（ 参见材料部分）提供的用户手册中描述的相应的舞台上的地位一起保存所有LM的图像。 </li></ol> 8.溅射镀膜<ol><li>从LM和电源取出样品架。确保样品保持稳定地固定在保持器内。 </li><li>修复铜CONDuctive磁带上围绕LED的抛光样品表面和样品架接触。切勿用磁带的投资回报。 </li><li>用箔覆盖样品座，并准备类似于样品直径（ 约 5毫米）的一个窗口。固定在箔内彻底样本保持器，使得所述窗口是直接在样品上方。 </li><li>样品架放入溅射镀膜机确保样品表面能够涂的接收者。溅射一个5nm厚的碳层到所述样品表面（从碳棒）。移动样品架从溅射镀膜机的并取出箔。 </li></ol> 9. SEM测量设置<ol><li>安装样品架到SEM适配器，并将其放置在SEM的机动阶段。泵真空室。 </li><li>通过保存作为参考点的校准标记的位置校准的SEM内样品保持器的位置。 注:此步骤包括半自动P A详细说明rocedure在用户手册（ 参见材料节）中所述。 </li><li>定义坐标从LM改造SEM阶段的投资回报直接搬迁，为LM图像中导航。此步骤也可以自动通过软件在用户手册（ 参见材料节）中描述的进行。 </li></ol> 10. SEM分析<ol><li>移动舞台上显示样品ROI和在相同的位置在LM进行SEM分析。 </li><li>选择面成像"SE检测 "。选择20千电子伏的电子能量，设定光圈30微米，在8.7毫米的工作距离的样本位置。 </li><li>选择材质对比" 疯牛病检测 "。选择20千电子伏的电子能量，设定光圈30微米，在8.7毫米的工作距离的样本位置。 </li><li>选择元素映射"EDX检测 "。选择20千电子伏的电子能量，设定光圈60微米，并在9毫米的工作距离的样本位置。检测下列元素:Y，铝，钙，硅，镓，金，镍和铜。 </li></ol> 11.图像处理<ol><li>通过在从LM和SEM图像和由另外的图像的处理中由供应商（ 参见材料节）所提供的用户手册中所述选择相同点执行LM和SEM图像的叠加。 </li></ol>

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The authors have nothing to disclose.

这种多峰方法的优点包括在所获取的数据的位置相关的相关性。这里所描述的多模式应与每个单独的技术后续分析进行对比。例如，在LM可见发光特性可以为使用SEM / EDS检测挂成分。经CT获得的卷信息可以在以靶向方式制备横截面的深度分析进行扩展。 CT数据还使得能够在随后显微镜调查兴趣可能领域快速定位。此处所描述的方法是最后的几个技术，这使光学性质的微结构，甚至到亚微米结构细节的联动之一。光学缺陷或不均匀性可以明确和可追溯性被链接到设备的结构或电缺陷。 这里提出的方法依赖于优良和可靠的数据obtaine由每个所使用的成像技术ð。这是至关重要的尤其是鉴于在CT结果其必须足够精确，以获得小的区域中明确的结构信息1毫米3和远低于。如果不确定性是适合使设备完好电子将是不可能的横截面平面的位置太大成功策划。然而，不仅确实截面的正确位置，确保电可操作性，但是，此外，在研磨过程中和抛光工艺护理有，为了避免由机械应力或不需要的颗粒短路设备（ 例如 ，将要采取从研磨介质）导入到样品表面。 如果LED证明，尽管切削平面和精心准备的正确位置被短路，这可能是有用的表面而造成这种电气故障颗粒重新检查。样品苏仔细抛光rface建议用于解决问题在这样的情况下，通常是该装置的可操作性可以通过这一措施来建立。样品表面的进一步改进通过使用离子研磨技术是可能的。由此显微镜观察到的区域将是最佳的平滑和无缺陷的。一旦横截面已被成功制备的CLEM样本保持器的处理，必须以最大的努力进行。相对于支架的样品的小的移动将使覆盖不精确，并破坏了该技术的优点是由于这样的事实，在这些情况下的ROI将再次必须手动找到。 该工作流程仅限于样品，允许在CT成像（X射线吸收既不能过高也不能过低）足够的对比度差异。与小尺寸的样品是首选。样品的纵横比必须是这样的，不太少量需要横断面制备被除去。在这个实施例1.2毫米的去除，如果该距离小很多更精确的研磨或抛光技术需要应用， 例如 ，离子铣。的光学显微镜的分辨率衍射极限可以部分地克服用于不同类型的由ROI的后续SEM成像对比度。 这种技术可能被证明在微表征，失效分析或微电子器件的逆向工程极其有用的。由于几乎计划的试样分析的破坏部分的可能性，更精确的和计划的制剂可以进行减少分析时间和失败。 在将来向激光二极管和进一步半导体光源该技术的延伸是计划。在CLEM技术也将允许荧光显微镜的执行，可以在发光材料本（ 例如，激发和EMI的深度分析使裂变谱或发光寿命）。聚焦离子束（FIB）仪器可以用来加速样品制备，将使用FIB和CLEM工作流程（位置校准）准备这种情况下，样本将在FIB启动。使用FIB加工的另一种方法是将破坏性地确定在F​​IB-SEM样品的3D结构。 此处显示的结果是示出了技术作为这样的示例性的性质。很明显可以使用每个提到的技术在一个更为复杂的方式，因此我们也期望从未来的实验进一步的见解。

本文演示X射线计算机断层扫描（CT）与相关的光，并在发光二极管（LED）的深度表征示例性电子显微镜（CLEM）的组合的潜力和优势。使用这种技术，可以计划以这样的方式，当一个横截面可以用显微镜成像的电功能是在检体的其余部分保留了微制备的LED。该过程有几个独特的功能:一是规划编制微通过CT获得整个样本的渲染量的援助;其次，通过光学显微镜（LM）具有完整各种可用的成像技术（亮和暗场，偏振对比度等 ）的LED的观察;第三，在LM操作中LED的观察;第四，同一区域的充分各种各样的电子显微成像技术观察，包括备用电子lectron（SE）和背散射电子（BSE）的成像，以及能量色散X射线荧光光谱法（EDX）。 对于照明应用的LED被设计为发射白光，虽然在某些应用中的颜色变化可能是有利的。这个宽的发射不能由发射从一个化合物半导体来实现，由于LED在窄光谱带（ 大约 30纳米半峰全宽（FWHM））发射辐射。因此白色LED灯通常是由组合的蓝色LED与该短波长辐射转化成宽发射过大的光谱范围为1荧光体产生的。颜色可变的LED解决方案通常使用至少三种原色，这通常导致更高的市场价格。2 使用哪种CT，LM或者SEM的，当然是完善的（ 例如 ，在故障分析LED的3 - 15），然而，这里描述的所有三种技术全面和有针对性的组合可以提供新的见解，将使朝着有意义的表征结果更快的轨道。 从在CT感兴趣的区域（投资回报）​​可以识别和选择的封装器件的三维微观结构分析。与此非破坏性方法，电连接也可以识别并考虑用于进一步制备。二维横截面的确切制剂允许在操作所述装置的调查，尽管该方法的破坏性。横截面，现在可以通过CLEM 16,17使相同ROI的一个非常有效的，灵活的表征与LM以及扫描电镜来表征。通过这种方法，既显微技术的优点可以被组合。例如，感兴趣区在LM的快速识别后跟在SEM高分辨率成像。但此外，信息从相关将LM（ 例如 ，颜色，光学性质，粒度分布）利用SEM的可视化和分析技术（ 例如 ，颗粒大小，表面形貌，元素分布）允许的功能行为和显微白色LED内的更深的理解。

<table border="0" cellpadding="0" cellspacing="0" width="758">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">X-Ray Computer Tomograph</td>
			<td style="width:119px;">General Electric</td>
			<td style="width:139px;">not applicable</td>
			<td style="width:239px;">type: nanotom s research edition</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:263px;">acquisition software</td>
			<td style="width:119px;">General Electric</td>
			<td style="width:139px;">not applicable</td>
			<td>phoenix Datos| x2 acquisition and corresponding manual</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:263px;">reconstruction software</td>
			<td style="width:119px;">General Electric</td>
			<td style="width:139px;">not applicable</td>
			<td>phoenix Datos| x2 acquisition and corresponding manual</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">rendering software</td>
			<td style="width:119px;">Volume Graphics</td>
			<td style="width:139px;">not applicable</td>
			<td>VGStudio Max 2.2 and corresponding manual</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">grinder (manual)</td>
			<td style="width:119px;">Struers</td>
			<td align="right" style="width:139px;">5296327</td>
			<td>Labopol 21</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">sample holder</td>
			<td style="width:119px;">Struers</td>
			<td align="right" style="width:139px;">4886102</td>
			<td>UniForce</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">grinder (automated)</td>
			<td style="width:119px;">Struers</td>
			<td align="right" style="width:139px;">6026127</td>
			<td>Tegramin 25</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:263px;">epoxy resin/hardener</td>
			<td style="width:119px;">Struers</td>
			<td style="width:139px;">40200030/40200031</td>
			<td>Epoxy fix resin / Epoxy fix hardener</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Ethanol</td>
			<td style="width:119px;">Struers</td>
			<td align="right" style="width:139px;">950301</td>
			<td>Kleenol</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Light Microscope</td>
			<td style="width:119px;">Zeiss</td>
			<td style="width:139px;">not applicable</td>
			<td>Axio Imager M2m&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">Electron Microscope</td>
			<td style="width:119px;">Zeiss</td>
			<td style="width:139px;">not applicable</td>
			<td>Sigma&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">CLEM software</td>
			<td style="width:119px;">Zeiss</td>
			<td style="width:139px;">not applicable</td>
			<td>Axio Vision SE64 Rel.4.9 and corresponding manual</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">CLEM sample holder</td>
			<td style="width:119px;">Zeiss</td>
			<td style="width:139px;">432335-9101-000</td>
			<td>Specimen holder CorrMic MAT Universal B</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">SEM Adapter for CLEM sample holder</td>
			<td style="width:119px;">Zeiss</td>
			<td style="width:139px;">432335-9151-000</td>
			<td>SEM Adapter for Specimen holder CorrMic MAT Universal B</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">sputter coater</td>
			<td style="width:119px;">Quorum</td>
			<td style="width:139px;">not applicable</td>
			<td>Q150TES</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">EDS detector</td>
			<td style="width:119px;">R&#246;ntec</td>
			<td style="width:139px;">not applicable</td>
			<td>X-Flash 1106</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">solder</td>
			<td style="width:119px;">Stannol</td>
			<td align="right" style="width:139px;">535251</td>
			<td>type: HS10</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:263px;">LED</td>
			<td style="width:119px;">Lumileds</td>
			<td style="width:139px;">not applicable</td>
			<td>LUXEON Rebel warm white, research sample</td>
		</tr>
	</tbody>
</table>

in depth analyses of leds by a combination of x-ray computed tomography (ct) and light microscopy (lm) correlated with scanning electron microscopy (sem)

In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of micro-characterization, plays an important role. Commonly, different techniques like X-ray computed tomography (CT), light microscopy (LM) and scanning electron microscopy (SEM) are used separately. Similarly, the results have to be treated for each technique independently. Here a comprehensive study is shown which demonstrates the potentials leveraged by linking CT, LM and SEM. In depth characterization is performed on a white emitting LED, which can be operated throughout all characterization steps. Major advantages are: planned preparation of defined cross sections, correlation of optical properties to structural and compositional information, as well as reliable identification of different functional regions. This results from the breadth of information available from identical regions of interest (ROIs): polarization contrast, bright and dark-field LM images, as well as optical images of the LED cross section in operation. This is supplemented by SEM imaging techniques and micro-analysis using energy dispersive X-ray spectroscopy.

的特征在于LED被示出在图1中，它是发光LED具有1×1 mm 2的芯片尺寸和部分陶瓷发光颜色转换为白色。胶合LED在稍微倾斜的位置上的碳纤维条避免引起样品对称性的CT伪影（ 图2）。在CT测量的结果允许规划样品的横截面的位置，并确保局部磨损（ 图3和图4）后的电可操作性。所呈现的体积允许将功能结构，尤其是容易区分的电触头的定位由于相应的金属（金，铜，锡），这导致在下层的X射线图像的高对比度的高原子序数。如果该LED封装的基本结构是公知的，由有源区所占的体积（ 即 ，发光芯片），荧光粉，齐纳二极管和过模制光学很容易识别。有关进一步的准备中，将样品包埋在环氧树脂（ 图5）。设置电触点，以允许LED的操作。随后，将样品表面被除去，横截面根据由CT规划抛光。的横截面在LM成像。同时明照明和LED发光（ 图6）允许从LED芯片和不同磷光体材料的蓝色发光的可视化连同此装置的结构设置。在这里，在不同的功能层传播光，以及蓝色到红色和黄色的光子转换可以在视觉上本地化。的明反差重叠图显示的Au接触和包装材料，如Si的位置。 样品表面的溅射涂覆和转移CL后EM样品架，以SEM，投资回报率成像与BSE对比（ 图7）。在与LM的相关电子显微镜允许以下扣除:红色荧光体（高对比度）被包埋在基质（低对比度，大概硅氧烷），其也作为粘合剂用在顶部的陶瓷黄色发光转换层。颗粒尺寸和形态的转换层可以很容易地被识别，和红色发光材料的分布的均匀性也可以被评估。这种分析还给出了两种磷光体的相对数量的估计。 关联的两种方法的信息（ 图8）连接在附加的ROI的功能行为的设备的微观结构。这里，最后，扣除在作为与识别的，可以确认该物质的性质之前的步骤进行。通过定量EDS测量电<html>对此语句，该LED封装的确切成分可以很容易地被识别:即 InGaN有源区，体CaAlSiN 3:Eu的红色荧光体和Y 3的Al 5 O 12:Ce的黄色发光陶瓷磷光体。 <img alt="图1" src="/files/ftp_upload/53870/53870fig1.jpg" /> 图1. LED。用于表征LED。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/53870/53870fig2.jpg" /> 图2为样本编制CT，LED安装在倾斜位置上的碳纤维栏上。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <html>内容"FO:保together.within页="1"&gt; <img alt="图3" src="/files/ftp_upload/53870/53870fig3.jpg" /> 图3呈现的体积。渲染体积CT测量的结果。秤可以从方形陶瓷荧光体片覆盖发光芯片，为1毫米×1毫米的大小进行估计。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/53870/53870fig4.jpg" /> 图4.计划的横截面。截面的虚拟规划，确保电力的可操作性。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 3870fig5.jpg"/&gt; 图5.嵌入式样品，样品嵌入在电接触导线的环氧树脂。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig5large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图6" src="/files/ftp_upload/53870/53870fig6.jpg" /> 横截面图6. LM形象。同声明视场照明成像点亮LED的横截面。比例尺为20微米。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig6large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图7" src="/files/ftp_upload/53870/53870fig7.jpg" /> 图7的横截面的SEM图像。同样ROI的BSE图像， 如图6。比例尺是20微米。 &lt;A HREF ="htt​​ps://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig7large.jpg"目标="_空白"&gt;点击此处查看该图的放大版本。 <img alt="图8" src="/files/ftp_upload/53870/53870fig8.jpg" /> 横截面的图8 CLEM图像和LM的覆盖SEM图像（从左至右）:在LM明相反，发光的对比度（LM）和背散射电子（SEM）的能量色散X射线荧光在SEM中映射叠加（ Ÿ浅黄色，绿色铝，钙红色，绿松石硅，嘎蓝色，黄色的金，镍粉，铜棕色）。比例尺为10微米。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53870/53870fig8large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

Watch this Scientific Journal Video about In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography CT and Light Microscopy LM Correlated with Scanning Electron Microscopy SEM at JoVE.co

In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography CT and Light Microscopy LM Correlated with Scanning Electron Microscopy SEM

一种有源光器件的全面的微特征的工作流程概述。它包含CT，LM和扫描电镜结构以及功能调查。该方法被证明为白色LED可仍然表征期间进行操作。

在通过X射线计算机断层扫描（CT）和与扫描电子显微镜相关光学显微镜（LM）的一个组合的LED深度分析（SEM）的

In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of ...

in-depth-analyses-leds-combination-x-ray-computed-tomography-ct-light

Nanyang Technological University

Research

JoVE Journal

Engineering

In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography (CT) and Light Microscopy (LM) Correlated with Scanning Electron Microscopy (SEM)

9.2K 次观看.  Hamm-Lippstadt University of Applied Sciences. 一种有源光器件的全面的微特征的工作流程概述。它包含CT，LM和扫描电镜结构以及功能调查。该方法被证明为白色LED可仍然表征期间进行操作。 

视频: In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography CT and Light Microscopy LM Correlated with Scanning Electron Microscopy SEM

Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction.
Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of &gt; 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm.
Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed.

The use of energy dispersive X-ray tomography in the scanning transmission electron microscope to characterize elemental distributions within single nanoparticles in three dimensions is described.

能量色散X射线断层摄影术对个人纳米3D元素映射

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial ...

科研

工程学

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 ...

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is reported. The measurements were demonstrated at the 1-BM bending magnet beamline of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). By using a 2-D checkerboard &#960;/2 phase-shift grating, transverse coherence lengths were obtained along the vertical and horizontal directions as well as along the 45&#176; and 135&#176; directions to the horizontal direction. Following the technical details specified in this paper, interferograms were measured at different positions downstream of the phase grating along the beam propagation direction. Visibility values of each interferogram were extracted from analyzing harmonic peaks in its Fourier Transformed image. Consequently, the coherence length along each direction can be extracted from the evolution of visibility as a function of the grating-to-detector distance. The simultaneous measurement of coherence lengths in four directions helped identify the elliptical shape of the coherence area of the Gaussian-shaped X-ray source. The reported technique for multiple-direction coherence characterization is important for selecting the appropriate sample size and orientation as well as for correcting the partial coherence effects in coherence scattering experiments. This technique can also be applied for assessing coherence preserving capabilities of X-ray optics.

The measurement protocol and data analysis procedure are given for obtaining transverse coherence of a synchrotron radiation X-ray source along four directions simultaneously using a single 2-D checkerboard phase grating. This simple technique can be applied for complete transverse coherence characterization of X-ray sources and X-ray optics.

使用2-D棋盘相位光栅X射线束相干测量沿多个方向

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is ...

Dynamic Pore-scale Reservoir-condition Imaging of Reaction in Carbonates Using Synchrotron Fast Tomography

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve geologic seals and allow CO2 to escape. However, the dissolution processes at reservoir conditions are poorly understood. Thus, time-resolved experiments are needed to observe and predict the nature and rate of dissolution at the pore scale. Synchrotron fast tomography is a method of taking high-resolution time-resolved images of complex pore structures much more quickly than traditional &#181;-CT. The Diamond Lightsource Pink Beam was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 hours. The images were segmented and the porosity and permeability were measured using image analysis and network extraction. Porosity increased uniformly along the length of the sample; however, the rate of increase of both porosity and permeability slowed at later times.

Synchrotron fast tomography was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 h.

用同步快速反应层析成像动态孔隙规模油藏条件下成像碳酸盐

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve ...

Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a microfluidic chamber assembled in the specimen holder for Transmission Electron Microscopy (TEM) and STEM. The microfluidic system consists of two silicon microchips supporting thin Silicon Nitride (SiN) membrane windows. This article describes the basic steps of sample loading and data acquisition. Most important of all is to ensure that the liquid compartment is correctly assembled, thus providing a thin liquid layer and a vacuum seal. This protocol also includes a number of tests necessary to perform during sample loading in order to ensure correct assembly. Once the sample is loaded in the electron microscope, the liquid thickness needs to be measured. Incorrect assembly may result in a too-thick liquid, while a too-thin liquid may indicate the absence of liquid, such as when a bubble is formed. Finally, the protocol explains how images are taken and how dynamic processes can be studied. A sample containing AuNPs is imaged both in pure water and in saline.

This protocol describes the operation of a liquid flow specimen holder for scanning transmission electron microscopy of AuNPs in water, as used for the observation of nanoscale dynamic processes.

使用扫描透射电子显微镜研究纳米大小的物体的动态过程中的液体

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a ...

Precision Milling of Carbon Nanotube Forests Using Low Pressure Scanning Electron Microscopy

A nanoscale fabrication technique appropriate for milling carbon nanotube (CNT) forests is described. The technique utilizes an environmental scanning electron microscope (ESEM) operating with a low pressure water vapor ambient. In this technique, a portion of the electron beam interacts with the water vapor in the vicinity of the CNT sample, dissociating the water molecules into hydroxyl radicals and other species by radiolysis. The remainder of the electron beam interacts with the CNT forest sample, making it susceptible to oxidation from the chemical products of radiolysis. This technique may be used to trim a selected region of an individual CNT, or it may be used to remove hundreds of cubic microns of material by adjusting ESEM parameters. The machining resolution is similar to the imaging resolution of the ESEM itself. The technique produces only small quantities of carbon residue along the boundaries of the cutting zone, with minimal effect on the native structural morphology of the CNT forest.

Low pressure scanning electron microscopy in a water vapor ambient is used to machine nanoscale to microscale features in carbon nanotube forests.

碳纳米管森林精密铣床使用低压扫描电子显微镜

A nanoscale fabrication technique appropriate for milling carbon nanotube (CNT) forests is described. The technique utilizes an environmental scanning ...

Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation displays and solid-state lighting technologies. The brightness and efficiency of blue QDs-based light-emitting diodes (LEDs) remain inferior to their red and green counterparts, due to the inherently unfavorable energy levels of different colors of light. To solve these problems, a device structure should be designed to balance the injection holes and electrons into the emissive QD layer. Herein, through a simple autoxidation strategy, pure blue QD-LEDs which are highly bright and efficient are demonstrated, with a structure of ITO/PEDOT:PSS/Poly-TPD/QDs/Al:Al2O3. The autoxidized Al:Al2O3 cathode can effectively balance the injected charges and enhance radiative recombination without introducing an additional electron transport layer (ETL). As a result, high color-saturated blue QD-LEDs are achieved with a maximum luminance over 13,000 cd m-2, and a maximum current efficiency of 1.15 cd A-1. The easily controlled autoxidation procedure paves the way for achieving high-performance blue QD-LEDs.

A protocol is presented for fabricating high-performance, pure blue ZnCdS/ZnS-based quantum dots light-emitting diodes by employing an autoxidized aluminum cathode.

采用部分氧化铝阴极增强电子注入和激子约束的纯蓝色量子点发光二极管

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation ...

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.

矿物和岩石样品的同步辐射 x 射线 Microdiffraction 和荧光成像

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder ...

X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells

X-ray beam induced current (XBIC) measurements allow mapping of&#160;the nanoscale performance of electronic devices such as solar cells. Ideally, XBIC is employed simultaneously with other techniques within a multi-modal X-ray microscopy approach. An example is given herein combining XBIC with X-ray fluorescence to enable point-by-point correlations of the electrical performance with chemical composition. For the highest signal-to-noise ratio in XBIC measurements, lock-in amplification plays a crucial role. By this approach, the X-ray beam is modulated by an optical chopper upstream of the sample. The modulated X-ray beam induced electrical signal is amplified and demodulated to the chopper frequency using a lock-in amplifier. By optimizing low-pass filter settings, modulation frequency, and amplification amplitudes, noise can efficiently be suppressed for the extraction of a clear XBIC signal. A similar setup can be used to measure the X-ray beam induced voltage (XBIV). Beyond standard XBIC/XBIV measurements, XBIC can be measured with bias light or bias voltage applied such that outdoor working conditions of solar cells can be reproduced during in-situ and operando measurements. Ultimately, the multi-modal and multi-dimensional evaluation of electronic devices at the nanoscale enables new insights into the complex dependencies between composition, structure, and performance, which is an important step towards solving the materials&#39; paradigm.

A setup for X-ray beam induced current measurements at synchrotron beamlines is described. It unveils the nanoscale performance of solar cells and extends the suite of techniques for multi-modal X-ray microscopy. From wiring to signal-to-noise optimization, it is shown how to perform state-of-the-art XBIC measurements at a hard X-ray microprobe.

太阳能电池多模态X射线显微镜的X射线光束诱导电流测量

X-ray beam induced current (XBIC) measurements allow mapping of&#160;the nanoscale performance of electronic devices such as solar cells. Ideally, XBIC is ...

Graphene-Assisted Quasi-van der Waals Epitaxy of AlN Film on Nano-Patterned Sapphire Substrate for Ultraviolet Light Emitting Diodes

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers are directly grown on NPSS using catalyst-free atmospheric-pressure chemical vapor deposition (APCVD). By applying nitrogen reactive ion etching (RIE) plasma treatment, defects are introduced into the graphene film to enhance chemical reactivity. During metal-organic chemical vapor deposition (MOCVD) growth of AlN, this N-plasma treated graphene buffer enables AlN quick growth, and coalescence on NPSS is confirmed by cross-sectional scanning electron microscopy (SEM). The high quality of AlN on graphene-NPSS is then evaluated by X-ray rocking curves (XRCs) with narrow (0002) and (10-12) full width at half-maximum (FWHM) as 267.2 arcsec and 503.4 arcsec, respectively. Compared to bare NPSS, AlN growth on graphene-NPSS shows significant reduction of residual stress from 0.87 GPa to 0.25 Gpa, based on Raman measurements. Followed by AlGaN multiple quantum wells (MQWS) growth on graphene-NPSS, AlGaN-based deep ultraviolet light-emitting-diodes (DUV LEDs) are fabricated. The fabricated DUV-LEDs also demonstrate obvious, enhanced luminescence performance. This work provides a new solution for the growth of high quality AlN and fabrication of high performance DUV-LEDs using a shorter process and less costs.

A protocol for graphene-assisted growth of high-quality AlN films on nano-patterned sapphire substrate is presented.

紫外发光二极管纳米图案蓝宝石基板的AlN薄膜的石墨烯辅助准范德瓦尔斯皮Taxy

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers ...