Soft X-ray detection and photon counting spectroscopy with commercial 4H-SiC Schottky photodiodes

The results of electrical characterisation and X-ray detection measurements of two different active area (0.06 mm and 0.5 mm) commercial 4H-SiC Schottky photodiodes at room temperature are reported. The devices exhibited low dark currents (less than 10 pA) even at a high electric field strengths (403 kV/ cm for 0.06 mm diodes; 227 kV/cm for 0.5 mm diodes). The results of the X-ray measurements indicate that the diodes can be used as photon counting spectroscopic X-ray detectors with modest energy resolutions: FWHM at 5.9 keV of 1.8 keV and 3.3 keV, for the 0.06 mm and 0.5 mm devices, respectively. Noise analysis of the photodiodes coupled to a custom low noise charge sensitive preamplifier is also presented. & 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).