Impact of threading dislocations on the design of GaAs and InGaP/GaAs solar cells on Si using finite element analysis

Abstract—We investigate the impact of threading dislocation densities on the photovoltaic performance of single-junction (1J) n+ /p GaAs and dual-junction (2J) n+ /p InGaP/GaAs solar cells on Si substrate. Using our calibrated model, simulation predicts an efficiency of greater than 23 % for a 1J GaAs cell on Si at AM1.5G spectrum at a threading dislocation density of 106 cm−2. The design of a metamorphic 2J InGaP/GaAs solar cell on Si was optimized by tailoring the 2J cell structure on Si to achieve current matching between the subcells, taking into account a threading dislocation density of 106 cm−2. Finally, we present a novel and an optimized 2J InGaP/GaAs solar cell design on Si at a thread-ing dislocation density of 106 cm−2, which exhibited a theoretical conversion efficiency of greater than 29 % at AM1.5G spectrum, indicating a path for viable III–V multijunction cell technology on Si. Index Terms—III–V semiconductor materials, charge carrier lifetime, photovoltaic cells, semiconductor device modeling. I