InGaAsP Radiation Hardness and Post Irradiation Regeneration Behavior

As an answer to increased demand for more radiation tolerant solar cells for space applications, we investigate the dependence of radiation hardness of III-V compounds on composition of InGaAsP. Four solar cells with different composition were grown on InP and metamorphically on GaAs and irradiated with 1 MeV electrons. A simulation-based analysis was used to determine the material specific irradiation damage. In addition, the regeneration ability is investigated under typical operating conditions (60 degrees C and AM0 illumination) and under the ECSS standard. While a clear decrease in radiation damage compared to GaAs is observed in all samples, the effect is stronger with increasing InP-fraction. The irradiation induced defect recombination coefficient can be described with a linear function of InP-fraction.