Zhao, S, Lioliou, G and Barnett, A M (2017) Temperature dependence of commercial 4H-SiC UV Schottky photodiodes for X-ray detection and spectroscopy. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 859. pp. 76-82. ISSN 0168-9002

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Abstract

Two commercial-off-the-shelf (COTS) 4H-SiC UV photodiodes have been investigated for their suitability as low-cost high temperature tolerant X-ray detectors. Electrical characterisation of the photodiodes which had different active areas (0.06 mm² and 0.5 mm²) is reported over the temperature range 0 °C to 140 °C together with measurements of the X-ray photocurrents generated when the detectors were illuminated with an 55Fe radioisotope X-ray source. The 0.06 mm² photodiode was also investigated as a photon counting spectroscopic X-ray detector across the temperature range 0 °C to 100 °C. The depletion widths (at 120 V reverse bias) of the two diodes were found to be 2.3 µm and 4.5 µm, for the 0.06 mm² and 0.5 mm² detectors respectively, at 140 °C. Both devices had low leakage currents (<10 pA) at temperatures ≤40 °C even at high electric field strengths (500 kV/cm for 0.06 mm² diode; 267 kV/cm for 0.5 mm² diode). At 140 °C and similar field strengths (514 kV/cm for 0.06 mm² diode; 269 kV/cm for 0.5 mm2 diode), the leakage currents of both diodes were <2 nA (corresponding to leakage current densities of 2.4 µA/cm² and 0.3 µA/cm² for each diode respectively). The results demonstrated that both devices could function as current mode detectors of soft X-rays at the temperatures <80 °C and that when coupled to a low noise charge sensitive preamplifier, the smaller diode functioned as a photon counting spectroscopic X-ray detector at temperatures ≤100 °C with modest energy resolution (1.6 keV FWHM at 5.9 keV at 0 °C; 2.6 keV FWHM at 5.9 keV at 100 °C). Due to their temperature tolerance, wide commercial availability, and the radiation hardness of SiC, such detectors are expected to find utility in future low-cost nanosatellite (cubesat) missions and cost-sensitive industrial applications.

Item Type:	Article
Keywords:	X-ray detector; Photodiode; Silicon carbide; COTS; Commercial off the shelf; Temperature dependence
Schools and Departments:	School of Engineering and Informatics > Engineering and Design
Research Centres and Groups:	Sensor Technology Research Centre
Subjects:	Q Science > QB Astronomy Q Science > QC Physics
Depositing User:	Shifan Zhao
Date Deposited:	10 Apr 2017 11:13
Last Modified:	04 Dec 2017 14:01
URI:	http://sro.sussex.ac.uk/id/eprint/61161

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