Irradiation of 4H-SiC UV detectors with heavy ions

Ultraviolet (UV) photodetectors based on Schottky barriers to 4H-SiC are formed on lightly doped n-type epitaxial layers grown by the chemical vapor deposition method on commercial substrates. The diode structures are irradiated at 25$^\circ$C by 167-MeV Xe ions with a mass of 131 amu at a fluence of 6 $\cdot$ 10$^9$ cm$^{-2}$. Comparative studies of the optical and electrical properties of as-grown and irradiated structures with Schottky barriers are carried out in the temperature range 23–180$^\circ$C. The specific features of changes in the photosensitivity and electrical characteristics of the detector structures are accounted for by the capture of photogenerated carriers into traps formed due to fluctuations of the conduction-band bottom and valence-band top, with subsequent thermal dissociation.