Low Energy Proton Damage to Solar Cells

Various types of silicon solar cells have been irradiated with 4.6 - 4.8 Mev protons in two separate experiments. In the first experiment, variations included the bulk material, impurity concentration, and oxygen concentration; the second experiment involved the cells of various manufacturers. Changes in diffusion length, spectral response, and efficiency under sun-like illumination are presented. Annealing effects in terms of the aforermentioned parameters are given. Comparison of the effects of this damage to that of 1 Mev electrons is made. Some preliminary results on the effects of proton damage to GaAs photovoltaic cells are also mentioned.