Current-limiting behavior in multijunction solar cells

Experimental measurements on tandem GaInAsP/InGaAs concentrator solar cells are presented that demonstrate how the short-circuit current can shift from that of the higher current subcell to that of the lower current subcell as irradiance increases. Theoretical modeling illustrates how this can occur when the current-limiting subcell has a noticeably nonzero slope in its current-voltage curve near short-circuit, and should be general to all series-connected multijunction cells of this nature.