Application of displacement damage dose analysis to low-energy protons on silicon devices

Past work has shown that the degradation of GaAs solar cells in space radiation environments can be described with a single curve for all incident particle energies. This greatly simplifies the prediction of the performance of solar cells exposed to complex particle spectra. A similar approach has not been applied to silicon solar cells because the large diffusion length in silicon means that protons with relatively high energies lose a significant fraction of their energy in the active region of the cell. The proton energies are, therefore, not well defined in the device. In this paper, we show how the Monte Carlo code SRIM can be used to extend the displacement damage dose concept to cases where this occurs. The approach described can be used to analyze the response of complex device structures in the space environment.