Calculated and measured efficiencies of thin-film shallow-homojunction GaAs solar cells on Ge substrates

Abstract
By using a simple analytical model for GaAs solar cells with the nu+/p/p+ shallow‐homojunction structure, we have obtained good between compter calculations and experimental data for the external quantum efficiency and AM1 conversion efficiency of thin‐film GaAs cells with different values of + layer thickness grown on Ge substrates. The calculations yield values for material properties of the GaAs layers composing the cells and also permit the optimization of cell design parameters. In addition, the agreement between calculation and experiment demonstrates that the Ge substrates play a passive role. Thus we have succeeded in fabricating efficient thin‐film GaAs solar cells on non‐GaAs substrates.