Counteracting the Photovoltaic Effect in the Top Intergenerator Part of GaInP/GaAs/Ge Solar Cells

Resumo

The “top” intergenerator part situated between the GaInP and GaAs subcells (electric power generators) is analyzed. The shape of the light current–voltage characteristics and the V_oc–J_sc (open-circuit voltage–short-circuit current) dependence are examined. It is found that the p⁺–n⁺ tunnel heterojunction situated in the “top” intergenerator part can operate as a photoelectric source counteracting the base p–n junctions. In this case, the V_oc–J_sc characteristic has a descending part, and a sharp jump can be observed. This undesirable effect becomes weaker with increasing peak current of the tunnel junction.