Radiation hardness of a wide-bandgap material by the example of SiC nuclear radiation detectors

A polarization effect characteristically occurs in detectors based on wide-bandgap materials at considerable concentrations of radiation defects. The appearance of an electromotive force in the bulk of a detector is due to the long-term capture of carriers at deep levels related to radiation centers. The kinetics and strength of the polarization field have been determined. The carrier capture by the radiation centers can be controlled by varying the detector temperature, with a compromise reached at the “optimal” temperature between the generation current and the position of the deepest of the levels whose contribution to the loss of charge via capture is negligible. It has been found that the depth of a level of this kind (related to the energy gap width) is close to 1/3, irrespective of a material. The optimal temperatures are strictly individual for materials.