Simulation of a GaInP$_{2}$ - GaAs - GaInAsN - Ge Photovoltaic Cell for Space Applications

We use an open-source simulation software to design III-V multi-junction solar cells containing a dilute nitride subcell. We discuss the different modeling techniques in terms of physical models and numerical methods, and provide an educated guess for a GaInP$_{2}$ - GaAs - GaInAsN - Ge lattice-matched 4-junction solar cell performance assessment. We suggest a way to ensure an effective computation of the main output values of an open-source Poisson-Drift-Diffusion solver for multi-junction solar cell analysis. An optimization of a multi-junction cell including a n-i-p subcell is performed, starting from basic theoretical considerations, to the use of a double-layer anti-reflective coating to target the most limiting subcell, and then with an optimization of the n-i-p architecture in the 1 eV subcell with respect to the GaInAsN layer properties. We show that the detrimental effects of low diffusion lengths in the GaInAsN layer can be alleviated by taking advantage of field-assisted collection.