Improving the radiation hardness of space solar cells via nanophotonic light trapping

We show that the radiation-hardness of space solar cells can be significantly improved by employing nanophotonic light trapping. Two light-trapping structures are investigated in this work. In the first, an array of Al nanoparticles is embedded within the anti-reflection coating of a GaInP/InGaAs/Ge solar cell. A combined experimental and simulation study shows that this structure is unlikely to lead to an improvement in radiation hardness. In the second, a diffractive structure is positioned between the middle cell and the bottom cell. Computational results, obtained using an experimentally validated electro-optical simulation tool, show that a properly designed light-trapping structure in this position can lead to a relative 10% improvement in the middle-cell photocurrent at end-of-life.