Quantifying the performance of a hybrid pixel detector with GaAs:Cr sensor for transmission electron microscopy

Kirsty A Paton; Matthew C Veale; Xiaoke Mu; Christopher S Allen; Dzmitry Maneuski; Christian Kübel; Val O'Shea; Angus I Kirkland; Damien McGrouther

doi:10.1016/j.ultramic.2021.113298

Quantifying the performance of a hybrid pixel detector with GaAs:Cr sensor for transmission electron microscopy

Ultramicroscopy. 2021 Aug:227:113298. doi: 10.1016/j.ultramic.2021.113298. Epub 2021 Apr 29.

Authors

Kirsty A Paton¹, Matthew C Veale², Xiaoke Mu³, Christopher S Allen⁴, Dzmitry Maneuski⁵, Christian Kübel⁶, Val O'Shea⁵, Angus I Kirkland⁴, Damien McGrouther⁵

Affiliations

¹ Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, G12 8QQ, UK. Electronic address: kirsty.paton@glasgow.ac.uk.
² UKRI Science & Technology Facilities Council, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK.
³ Karlsruhe Nano Micro Facility, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
⁴ Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK; electron Physical Sciences Imaging Centre (ePSIC), Diamond Lightsource Ltd., Didcot, OX11 0DE, UK.
⁵ Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, G12 8QQ, UK.
⁶ Karlsruhe Nano Micro Facility, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany; Department of Materials and Earth Science, Technische Universität Darmstadt and Karlsruhe Institute of Technology, Otto-Berndt-Str. 3, 64287 Darmstadt, Germany.

PMID: 34051540
DOI: 10.1016/j.ultramic.2021.113298

Abstract

Hybrid pixel detectors (HPDs) have been shown to be highly effective for diffraction-based and time-resolved studies in transmission electron microscopy, but their performance is limited by the fact that high-energy electrons scatter over long distances in their thick Si sensors. An advantage of HPDs compared to monolithic active pixel sensors is that their sensors do not need to be fabricated from Si. We have compared the performance of the Medipix3 HPD with a Si sensor and a GaAs:Cr sensor using primary electrons in the energy range of 60-300 keV. We describe the measurement and calculation of the detectors' modulation transfer function (MTF) and detective quantum efficiency (DQE), which show that the performance of the GaAs:Cr device is markedly superior to that of the Si device for high-energy electrons.

Keywords: DQE; Direct electron detector; Hybrid pixel detector; MTF; Transmission electron microscopy.