Irradiation and measurement of solar cells at low intensity, low temperature (LILT) conditions

This paper presents measurement and analysis of triple junction InGaP/GaAs/Ge solar cells after irradiation and measurement under low temperature and low intensity (LILT) conditions. The goal of these experiments was to quantify any annealing effects that might emerge after irradiation at low temperature and subsequent measurement after room temperature anneal. This was accomplished by using the facility at JAEA, which enables simultaneous irradiation and measurement at temperature without breaking vacuum. Low intensity illumination was attained by placing screens between the simulator and the low temperature chamber. Proton irradiation at 10 MeV and electron irradiation at 1 MeV were performed. Low temperature irradiations were followed by a room temperature annealing. Room temperature irradiations were also performed for comparison. The results show that cells irradiated at LILT recovers on order of 20% of the radiation-induced degradation in short circuit current after room temperature annealing.