Novel Correlated Energy-Loss and Cathodoluminescence Spectroscopy in the Transmission Electron Microscope

透射电子显微镜中新型相关能量损失和阴极发光光谱

• 批准号: EP/F02374X/1
• 负责人: Thomas Walther
• 金额: $ 36.5万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF02374X%2F1
• 关键词: Novel; Correlated; Energy; Loss; Cathodoluminescence

Many modern semiconductor devices are based on multiple layer structures or the lateral structuring of planar layers to locate charge carriers in specific positions. These so-called quantum domain structures can have unique (opto)electronic properties, depending on the design used for carrier confinement (quantum wells, quantum wires or quantum dots for confinement in two, one or zero dimensions of space, respectively). Various forms of spectroscopy can be used to investigate such materials, however, most lack the spatial resolution necessary to study individual nanostructures. Spectroscopy in a transmission electron microscope (TEM) has the unique advantage of being able to investigate such individual nanostructures embedded below the specimen surface at nanometre-scale spatial resolution in two dimensions. This project proposes to combine the rather new method of electron spectroscopic profiling (ELSP), a hybrid imaging-spectroscopy method based on electron energy-loss spectroscopy (EELS) in a transmission electron microscope equipped with imaging energy filter, and cathodoluminescence (CL) spectroscopy. While EELS provides chemical and electronic information, CL yields optical information. Hence, the combination of both methods in the same instrument provides a unique probe of the local optoelectronic properties of light-emitting quantum domain structures. It is intended to investigate in particular quantum well and quantum dot structures of compound semiconductors with spatial dimensions of only a few nanometres in one or three dimensions, respectively, which are only really accessible using a modern analytical TEM. In order to incorporate CL detection into the narrow high-resolution pole-piece of a high-quality field-emission (scanning) TEM an existing specimen holder will be modified in order to accommodate both a newly designed highly-efficient light collecting optical cavity and a fibre optic cable. The fibre optics will allow the user to connect the specimen holder to two external spectrometers, a small Czerny-Turner type spectrometer with silicon diode array detector for the ultraviolet-visible (UV-VIS) wavelength range important for wide-bandgap nitride semiconductors or a high-resolution optical grating diffractometer installed in another laboratory with cooled germanium detector for the infrared (IR) range, relevant for the study of arsenide based semiconductors.

许多现代半导体器件基于多层结构或平面层的横向结构化以将电荷载流子定位在特定位置。这些所谓的量子域结构可以具有独特的（光）电子特性，这取决于用于载流子限制的设计（分别用于限制二维、一维或零维空间的量子威尔斯、量子线或量子点）。各种形式的光谱学可以用来研究这些材料，然而，大多数缺乏研究单个纳米结构所需的空间分辨率。透射电子显微镜（TEM）中的光谱具有独特的优势，能够以纳米级的空间分辨率在两个维度上研究嵌入在样品表面下方的这种单独的纳米结构。本项目提出联合收割机结合相当新的电子光谱分析（ELSP）方法，一种基于电子能量损失谱（EELS）的混合成像光谱方法，在配备成像能量过滤器的透射电子显微镜，和阴极发光（CL）光谱。EELS提供化学和电子信息，CL产生光学信息。因此，这两种方法在同一仪器中的组合提供了一个独特的探针的发光量子域结构的局部光电性能。它的目的是调查特别是量子阱和量子点结构的化合物半导体的空间尺寸只有几个纳米在一个或三个维度，分别只有真正使用现代分析TEM访问。为了将CL检测纳入高质量场发射（扫描）TEM的窄高分辨率极片中，将修改现有的试样保持器，以容纳新设计的高效光收集光学腔和光纤电缆。光纤将允许用户将样品保持器连接到两个外部光谱仪，一个是小型Czerny-Turner型光谱仪，带有硅二极管阵列检测器，用于宽禁带氮化物半导体重要的紫外-可见（UV-VIS）波长范围，或者是安装在另一个实验室中的高分辨率光栅衍射仪，带有冷却锗检测器，用于红外（IR）范围，这与基于砷化物的半导体的研究有关。

项目成果

Electron microscopy of AlGaN-based multilayers for UV laser devices

用于紫外激光器件的 AlGaN 多层膜的电子显微镜

• DOI: 10.1088/1742-6596/241/1/012048
• 发表时间: 2010
• 期刊: Conference Series
• 作者: Lari L

Characterization of thickness, elemental distribution and band-gap properties in AlGaN/GaN quantum wells by aberration-corrected TEM/STEM

通过像差校正 TEM/STEM 表征 AlGaN/GaN 量子阱中的厚度、元素分布和带隙特性

• DOI: 10.1088/1742-6596/371/1/012014
• 发表时间: 2012
• 期刊: Conference Series
• 作者: Amari H

Accurate calibration for the quantification of the Al content in AlGaN epitaxial layers by energy-dispersive X-ray spectroscopy in a Transmission Electron Microscope

通过透射电子显微镜中的能量色散 X 射线光谱准确定量 AlGaN 外延层中的 Al 含量

• DOI: 10.1088/1742-6596/326/1/012028
• 发表时间: 2011
• 期刊: Conference Series
• 作者: Amari H

Nanoscale EELS analysis of elemental distribution and band-gap properties in AlGaN epitaxial layers

AlGaN 外延层中元素分布和带隙特性的纳米级 EELS 分析

• DOI: 10.1088/1742-6596/326/1/012039
• 发表时间: 2011
• 期刊: Conference Series
• 作者: Amari H

GaN-based radial heterostructure nanowires grown by MBE and ALD

MBE 和 ALD 生长的 GaN 基径向异质结构纳米线

• DOI: 10.1088/1742-6596/471/1/012039
• 发表时间: 2013
• 期刊: Conference Series
• 作者: Lari L