A two-level model for heavily irradiated silicon detectors

The Fermi level pinning at a boundary value of ≈ Ev+0.5 eV, observed in heavily irradiated silicon, has been described considering two main traps related to divacancy (V2) and carbon–oxygen complex (CiOi), with energy levels at Ec − 0.46 eV (acceptor) and Ev+0.36 eV (donor), respectively. The appearance of a double junction in irradiated p+/n/n+ silicon detectors is discussed in the framework of the proposed model.