A team of researchers from the University of Potsdam and HZB has identified loss processes in perovskite solar cells that limit their efficiency, and found that the most significant efficiency losses occur at the interface between the perovskite and transport layer.

In certain defects in the crystal lattice of the perovskite layer, charge carriers (i.e. electrons and "holes") that have been released by sunlight can recombine again and thus be lost. But whether these defects were located within the perovskite layer or at the interface between the perovskite layer and the transport layer was unclear until now.