Lioliu, G., Krysa, A. orcid.org/0000-0001-8320-7354 and Barnett, A. (2018) Energy response characterization of InGaP X-ray detectors. Journal of Applied Physics, 124 (19). 195704. ISSN 0021-8979
Abstract
Two custom-made In0.5Ga0.5P p+-i-n+ circular mesa spectroscopic X-ray photodiodes with different diameters (200 μm and 400 μm) and a 5 μm i layer have been characterized for their response to X-ray photons within the energy range 4.95 keV to 21.17 keV. The photodiodes, operating uncooled at 30 °C, were coupled, in turn, to the same custom-made charge-sensitive preamplifier. X-ray fluorescence spectra of high-purity calibration foils excited by a Mo target X-ray tube were accumulated. The energy resolution (Full Width at Half Maximum) increased from 0.79 ± 0.02 keV at 4.95 keV to 0.83 ± 0.02 keV at 21.17 keV, and from 1.12 ± 0.02 keV at 4.95 keV to 1.15 ± 0.02 keV at 21.17 keV, when using the 200 μm and 400 μm diameter devices, respectively. Energy resolution broadening with increasing energy was attributed to increasing Fano noise (negligible incomplete charge collection noise was suggested); for the first time, the Fano factor for In0.5Ga0.5P was experimentally determined to be 0.13, suggesting a Fano limited energy resolution of 145 eV at 5.9 keV. The charge output of each system had a linear relationship with photon energy, across the investigated energy range. The count rate of both spectroscopic systems increased linearly with varying X-ray tube current up to ∼105 photons s−1 cm−2 incident photon fluences. The development of In0.5Ga0.5P based spectrometers is particularly important for hard X/γ-ray astronomy, due to the material’s large linear X-ray and γ-ray absorption coefficients and the ability to operate uncooled at high temperatures.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 The Authors. This is an author produced version of a paper subsequently published in Journal of Applied Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 04 Dec 2018 15:47 |
Last Modified: | 04 Dec 2018 15:50 |
Published Version: | https://doi.org/10.1063/1.5057407 |
Status: | Published |
Publisher: | AIP Publishing |
Refereed: | Yes |
Identification Number: | 10.1063/1.5057407 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:139520 |