Interface engineering of high efficiency perovskite solar cells based on ZnO nanorods using atomic layer deposition

Despite the considerably improved efficiency of inorganic-organic metal hybrid perovskite solar cells (PSCs), electron transport is still a challenging issue. In this paper, we report the use of ZnO nanorods prepared by hydrothermal self- assembly as the electron transport layer in perovskite solar cells. The efficiency of the perovskite solar cells is significantly enhanced by passivating the interfacial defects via atomic layer deposition of Al₂O₃ monolayers on the ZnO nanorods. By employing the Al₂O₃ monolayers, the average power conversion efficiency of methylammonium lead iodide PSCs was increased from 10.33% to 15.06%, and the highest efficiency obtained was 16.08%. We suggest that the passivation of defects using the atomic layer deposition of monolayers might provide a new pathway for the improvement of all types of PSCs..