1-MeV-electron irradiation of GaInAsN cells

GaInAsN cells are measured to retain 93 /spl plusmn/ 3% and 89 /spl plusmn/ 4% of their original efficiency after exposure to 5 /spl times/ 10/sup 14/ and 1 /spl times/ 10/sup 15/ cm/sup -2/ 1-MeV electrons, respectively. The rate of degradation is not correlated with the performance at beginning of life (BOL). The depletion width remains essentially unchanged, increasing by < 1%. Temperature-coefficient data for GaInAsN cells are also presented. These numbers are used to project the efficiency of GaInAsN-containing multijunction cells. The GaInAsN junction is not currently predicted to increase the efficiencies of the multijunction cells. Nevertheless, GaInAsN-containing multijunction cell efficiencies are predicted to be comparable to those of the conventional structures, and even small improvements in the GaInAsN cell may lead to higher multijunction cell efficiencies, especially for high-radiation applications and when cell operating temperature is low.