It has been empirically established that for quantum confined p-i-n solar cells a high electric field across the i-region is necessary for an optimal extraction of carriers from the well. This restriction imposes an upper limit for the total thickness of the i-region beyond which severe performance degradations are reported. For a given material system, the best efficiency trade-off is often achieved in the vicinity of this critical i-region thickness where the open circuit voltage degradation remains minimal and a higher photocurrent is afforded by the larger number of wells. But, even for devices that satisfy this condition, occasionally severe open circuit voltage degradation occurs. Here, we show that this degradation is directly correlated to the carrier escape sequence from the wells and that a careful engineering of hole and electron confining potentials can be used to alleviate this shortcoming. © 2006 Materials Research Society.