Highly efficient planar heterojunction perovskite solar cells with sequentially dip-coated deposited perovskite layers from a non-halide aqueous lead precursor.

High-performance planar heterojunction (PHJ) perovskite solar cells (PrSCs) with MAPbI 3 perovskite films were fabricated using a facile, environmentally benign, efficient and low-cost dip-coating deposition approach on a bilayered ZnO/TiO 2 electron transport system from aqueous non-halide Pb(NO 3 ) 2 . Outstanding performance of PrSCs was achieved due to the PHJ configuration of FTO/TiO 2 /ZnO/MAPbI 3 /spiro-OMeTAD/MoO 3 /Ag. These PHJ PrSCs exhibited better performance and stability with thinner ZnO layers in contrast to those with mesoporous TiO 2 scaffolds, indicating that the thickness of the ZnO layer in the PHJ architecture significantly affected the surface coverage, morphology, crystallinity, and stability of the MAPbI 3 perovskite films processed by dip-coating deposition.