Temperature dependence of Al0.2Ga0.8As X-ray photodiodes for X-ray spectroscopy

Whitaker, M D C, Butera, S, Lioliou, G and Barnett, A M (2017) Temperature dependence of Al0.2Ga0.8As X-ray photodiodes for X-ray spectroscopy. Journal of Applied Physics, 122 (3). ISSN 0021-8979

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Two custom-made Al0.2Ga0.8As p+-i-n+ mesa X-ray photodiodes (200 μm diameter, 3 μm i layer) have been electrically characterised across the temperature range −20 °C to 60 °C. The devices were connected to a custom-made charge sensitive preamplifier to produce an AlGaAs photon-counting X-ray spectrometer. The devices' responses to illumination with soft X-rays from an 55Fe radioisotope X-ray source (Mn Kα = 5.9 keV; Mn Kβ = 6.49 keV) were investigated across the temperature range −20 °C to 20 °C. The best energy resolution (FWHM at 5.9 keV) achieved at 20 °C was 1.06 keV (with the detector at 10 V reverse bias). Improved FWHM was observed with the devices at temperatures of 0 °C (0.86 keV) and −20 °C (0.83 keV) with the photodiode reverse biased at 30 V. The average electron hole pair creation energy was experimentally measured and determined to be 4.43 eV ± 0.09 eV at 20 °C, 4.44 eV ± 0.10 eV at 0 °C, and 4.56 eV ± 0.10 eV at −20 °C.

Item Type: Article
Schools and Departments: School of Engineering and Informatics > Engineering and Design
Subjects: Q Science > QC Physics > QC0170 Atomic physics. Constitution and properties of matter Including molecular physics, relativity, quantum theory, and solid state physics
Q Science > QC Physics > QC0474 Radiation physics (General)
Depositing User: Michael Whitaker
Date Deposited: 22 Aug 2017 13:55
Last Modified: 02 Jul 2019 18:39
URI: http://sro.sussex.ac.uk/id/eprint/69899

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In situ X-ray Fluorescence Spectroscopy for Deep Sea Mining ApplicationsG1537STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCILST/M004635/1