New Aspects of Copper Electrode Metamorphosis in Perovskite Solar Cells

Abstract

Interaction of a copper electrode with methylammonium polyiodides is studied for the first time at the interfaces imitating hybrid perovskite solar cells. Along with a widely known copper corrosion product—CuI, a new MACu2I3 phase is found. The presence of lead derivatives as well as reaction temperature are shown to have a strong influence on the resulting corrosion products. The interplay between lead- and copper-containing iodides allows revealing either realistic chemical corrosion pathways or possible practical benefits from CuI crystallization and perovskite recovery caused by the copper–iodine chemical “drain” in the system.