Effect of neutron irradiation on epitaxial 4H-SiC PiN UV-photodiodes

4H-SiC UV-photodetectors based on full-epitaxial p + -p − -n + multilayer structures were fabricated. The diodes were irradiated with fast neutrons up to the fluence of 110 14 cm −2 . Current-voltage characteristics, life time of non-equilibrium charge carriers as well as photosensitivity spectra of the diodes before and after irradiation were investigated. The studies showed that PiN UV-photodiodes with base doping below 1·10 15 cm −3 retain their performance up to the fluence of 5·10 12 neutrons per cm 2 . The further increase in fast neutron fluence stimulates the creation of excessive deep recombination centers. This leads to degradation of I-V-characteristics, reduction of carrier life time and, consequently, to degradation of the photosensitivity of devices.