Analysis and modeling of the radiation response of multijunction space solar cells

The displacement damage dose methodology for analyzing and modeling the performance of dual- (2J) and triple-junction (3J) InGaP2/GaAs/Ge solar cells in a space radiation environment is presented. The foundations of the D-d methodology are described through a discussion of the basic radiation-induced damage mechanisms. The nonionizing energy loss (NIEL) is introduced, and it is shown how the effect of different radiations can be correlated on the basis of NIEL. Displacement damage dose (D-d) is defined, and electron and proton irradiation data from multijunction (MJ) solar cells are shown to correlate directly in terms of D-d. The use of the D-d method for predicting on-orbit cell performance is described, and the role played by protons with energies down to zero is quantified. A validation of the model is provided through accurate prediction of data from space flight experiments.