Stöger-Pollach Michael, Bukvišová Kristýna, Schwarz Sabine, Kvapil Michal, Šamořil Tomáš, Horák Michal
University Service Centre for Transmission Electron Microscopy (USTEM), Technische Universität Wien, Wiedner Hauptstraße 8-10, Wien 1040, Austria.
University Service Centre for Transmission Electron Microscopy (USTEM), Technische Universität Wien, Wiedner Hauptstraße 8-10, Wien 1040, Austria; Central European Institute of Technology (CEITEC), Brno University of Technology, Purkyňova 123, Brno 612 00, Czech Republic; Institute of Physical Engineering, Brno University of Technology, Technická 2, Brno 616 69, Czech Republic.
Ultramicroscopy. 2019 May;200:111-124. doi: 10.1016/j.ultramic.2019.03.001. Epub 2019 Mar 4.
Cathodoluminescence has attracted interest in scanning transmission electron microscopy since the advent of commercial available detection systems with high efficiency, like the Gatan Vulcan or the Attolight Mönch system. In this work we discuss light emission caused by high-energy electron beams when traversing a semiconducting specimen. We find that it is impossible to directly interpret the spectrum of the emitted light to the inter-band transitions excited by the electron beam, because the Čerenkov effect and the related light guiding modes as well as transition radiation is altering the spectra. Total inner reflection and subsequent interference effects are changing the spectral shape dependent on the sample shape and geometry, sample thickness, and beam energy, respectively. A detailed study on these parameters is given using silicon and GaAs as test materials.
自从出现了像Gatan Vulcan或Attolight Mönch系统这样高效的商用检测系统以来，阴极发光在扫描透射电子显微镜中引起了人们的兴趣。在这项工作中，我们讨论了高能电子束穿过半导体样品时引起的发光现象。我们发现，由于切伦科夫效应、相关的光导模式以及过渡辐射会改变光谱，因此不可能直接将发射光的光谱解释为由电子束激发的带间跃迁。全内反射和随后的干涉效应分别根据样品形状和几何结构、样品厚度以及束流能量改变光谱形状。以硅和砷化镓作为测试材料，对这些参数进行了详细研究。
