Theoretical analysis on GaAs sub-cell doping concentration for triple-junction solar cells irradiated by proton based on TCAD simulation

Abstract:

The degradation on the GaInP/GaAs/Ge triple-junction solar cells was irradiated by proton, and the solar cells with various GaAs sub-cell doping concentrations are modeled by the technology computer aided design (TCAD) simulation. The degradation results of related electrical parameters and external quantum efficiency (EQE) are studied. The degradation mechanism irradiated by proton is discussed. The short-circuit current, maximum power and conversion efficiency decrease with the increasing of GaAs sub-cell doping concentration. When the base doping concentration of GaAs sub-cell is 1×1016 cm-3, the degradation of short-circuit current is less than that of other base doping concentrations. Furthermore, under proton irradiation, with the increase of doping concentration of GaAs sub-cell, the open-circuit voltage first increases and then decreases. Meanwhile, when the base doping concentration of GaAs sub-cell is 2×1017 cm-3, the degradation of open-circuit voltage is less than that of other base doping concentrations. The research will provide the basic theories and device simulation method for GaInP/GaAs/Ge triple-junction solar cells radiation damage evaluation study and radiation hardening, and can provide guidance for the production of triple-junction solar cells in orbit.