Lioliou_2021_Mater._Res._Express_8_025909.pdf (896.38 kB)
Performance evaluation of a new 30 µm thick GaAs x-ray detector grown by MBE
journal contribution
posted on 2023-06-09, 23:11 authored by Grammatiki LioliouGrammatiki Lioliou, C L Poyser, J Whale, R P Campion, A J Kent, Anna BarnettAnna BarnettA circular mesa (400 µm diameter) GaAs p+-i-n+ photodiode with a 30 µm thick i layer was characterized for its performance as a detector in photon counting x-ray spectroscopy at 20 °C. The detector was fabricated from material grown by molecular beam epitaxy (MBE). An earlier MBE-grown detector fabricated using a different fabrication process and material from a different area of the same epiwafer was shown to suffer from: relatively high leakage current at high temperatures; a high effective carrier concentration that limited its depletion layer width; and material imperfections (butterfly defects) [Lioliou et al 2019 Nucl. Instrum. Methods Phys. Res. A 946 162670]. However, the new detector has better performance (lower leakage current and effective carrier concentration within the i layer). Using the new detector and low noise readout electronics, an energy resolution of 750 eV ± 20 eV Full Width at Half Maximum (FWHM) at 5.9 keV was achieved at 20 °C, equal to that reported for high quality GaAs detectors made from high quality material grown by metalorganic vapour phase epitaxy [Lioliou et al 2017 J. Appl. Phys. 122 244506]. The results highlight the substantially different performances of detectors made from the same epiwafer when the wafer qualities are not uniform and the effects of different fabrication processes.
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Publication status
- Published
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- Published version
Journal
Materials Research ExpressISSN
2053-1591Publisher
IOP PublishingExternal DOI
Issue
2Volume
8Page range
1-6Article number
a025909Department affiliated with
- Physics and Astronomy Publications
Research groups affiliated with
- Space Research Group Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2021-03-03First Open Access (FOA) Date
2021-03-03First Compliant Deposit (FCD) Date
2021-03-01Usage metrics
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