Electric Orbit Raising Radiation-Induced Coverglass Darkening and Its Impact on III-V Multijunction Solar Cell Performance

Electric orbit raising (EOR) radiation-induced coverglass (CG) damage reduces the amount of light that reaches underlying solar cells and decreases photoconversion efficiency. This article describes the modeling, simulation, and ground-based radiation tests using Qioptiq CMG borosilicate CG for five selected EOR trajectories, and the impact on the performance of III-V multijunction (MJ) solar cells. The CG optical transmission loss reaches a maximum of ∼20% around 350 nm. However, the spectral response of the MJ solar cells at this wavelength is minimal. The test results show a darkening related to solar cell performance degradation of up to 5% for the worst-case EOR trajectory.