NIEL Dose Analysis on triple and single junction InGaP/GaAs/Ge solar cells irradiated with electrons, protons and neutrons

Triple junction (InGaP/GaAs/Ge) and single junction (SJ) solar cells were irradiated with electrons, protons and neutrons. The degradation of remaining factors was analyzed as function of the induced Displacement Damage Dose (DDD) calculated by means of the SR-NIEL (Screened Relativistic Non Ionizing Energy Loss) approach. In particular, the aim of this work is to analyze the variation of the solar cells remaining factors due to neutron irradiation with respect to those previously obtained with electrons and protons. The current analysis confirms that the degradation of the P-max electrical parameter is related by means of the usual semi-empirical expression to the displacement dose, independently of type of the incoming particle. I-sc and V-oc parameters were also measured as a function of the displacement damage dose. Furthermore, a DLTS analysis was carried out on diodes -with the same epitaxial structure as the middle sub-cell - irradiated with neutrons.