Single junction GaAs - Ge stacked tandem cell

In this work, a GaAs/Ge single junction stacked thin-film solar cell is demonstrated using physics based TCAD simulation The results are compared to a single junction thin film GaAs solar cell. The results show an increase in the V_oc and J_sc up to 7% and 12% respectively, which enhanced the absolute efficiency by 4% with the Ge layer. This increase in the current is due to the increase in the utilized spectrum in the long wavelength range. In addition, we studied the effect of Ge and GaAs thickness in the performance of the GaAs/Ge stacked cell.