Counteracting the photovoltaic effect in the top intergenerator part of GaInP/GaAs/Ge solar cells

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.