Development of a high-efficiency DF-STEM detector

Electron Microscopy and Analysis Group Conference 2013

Kaneko, T.^1 ; Saitow, A.^1 ; Fujino, T.^1 ; Okunishi, E.^1 ; Sawada, H.^1

JEOL Ltd., 1-2 Musashino 3-Chome, Akishima, Tokyo 196-8558, Japan^1

关键词: Accelerating voltages;    Carbon based materials;    Crystal scintillators;    Low accelerating voltage;    Luminescent quantum efficiency;    Powder scintillator;    Scanning transmission electron microscopes;    Single crystal substrates;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/522/1/012050/pdf
DOI  :  10.1088/1742-6596/522/1/012050

来源: IOP

【 摘 要 】

We experimentally evaluated the signal intensity produced by an electron on three types of scintillators. A powder scintillator showed high efficiency at a low accelerating voltage, whereas a single crystal scintillator showed high efficiency at higher accelerating voltages. On the basis of these characteristics, for a dark-field (DF) scanning transmission electron microscope (STEM), we have developed a new hybrid type scintillator, which consisted of a powder deposited on a single crystal substrate. The luminescent quantum efficiency of the hybrid scintillator was measured to be twice as large as that of the single crystal type detector at 60 kV and was about 8 times higher than that of the powder type detector at 300 kV. The developed detector has advantages of powder and single crystal type detectors, and covers the observation at the accelerating voltages from low to high voltages. Especially, it is useful for low voltage observations of carbon-based materials consisted of few atomic layers that produces weak scattering of electron.