The defect density in silicon resulting from proton bombardment has been caluclated from 10 MeV to 1.8 GeV. The results show that Rutherford scattering of the protons dominates defect production at low proton energies. Above 50 MeV, recoil nuclei resulting from spallation contribute significantly to the damage process. Good agreement between theory and experiments at 95.5 and 450 MeV is found, using the change in short circuit current density of solar cells and the change in minority carrier diffusion length as the experimental measures of lattice defects. The experimental results indicate that earlier theoretical models describing the slowing down of ions cannot satisfactorily explain the present observations.

• Received 5 November 1962

DOI:https://doi.org/10.1103/PhysRev.129.2454