Planar perovskite solar cells (PSCs) fabricated by intramolecular exchange with PbI2(DMSO) and PbI2(NMP) complexes and the high performance of these cells are described. Their films are easily deposited with a one-step spray-coating and were effectively converted into high-quality FAPbI3-based perovskite layers. PbI2(NMP)-derived PSCs yielded a power conversion efficiency as high as 19.5%, higher than that of PbI2(DMSO)-derived PSCs.