A striking correlation between the Fermi level in heavily radiation damaged semiconductors and at metal-semiconductor interfaces is presented. The correlation provides critical evidence supporting the defect model for Schottky-barrier formation. The Fermi-level energy for both situations corresponds to the average energy of the ${\mathrm{sp}}^{3}$ hybrid. In the case of GaAs, a detailed description of the Fermi-level stabilization caused by amphoteric dangling-bond-like defects is given.