An Analysis of Non-Uniform Proton Irradiation Damage in Silicon Solar Cells

Experimental data obtained on the degradation of the short-circuit current in 1-ohm-cm N/P silicon solar cells irradiated by low-energy, 0.1-3.0 MeV, protons were analyzed with the aid of an N-layer solar-cell model. The results show that the damage constant, K(Ep), rises less rapidly with decreasing proton energy, Ep, than it does at higher proton energies. The derived damage law can be analytically described as follows: K(Ep) = Ep ¿ E1 =.962 MeV E1 ¿ Ep =2.98 MeV where K0 = 1.92 × 10-5 p-1 C1 = 1.08 MeV-1 C2 = 0.85 This representation has been found adequate for incident proton energies of 0.5, 1, and 3 MeV and definitive for Ep ¿ 0.1 MeV. The value of Ko listed should be considered as representative only of the particular solar cells analyzed.