Organic–inorganic CH3NH3PbI3 (MAPbI3) inverted-structure perovskite films were prepared using Pb(CH3COO)2 (Pb(OAc)2) and CH3NH3I (MAI) as source materials. The structural, optical and photoelectronic properties of the resulting MAPbI3 films varied with the annealing temperature and the Pb(OAc)2/MAI molar ratio. A CH3NH3PbI3 film annealed at 80oC for 15min showed the highest power conversion efficiency (PCE) of more than 10%. It was also found that the Pb(OAc)2/MAI molar ratio greatly influenced the structure and morphology of the MAPbI3 films. A suitable amount of excess Pb(OAc)2 (about 5mol% excess Pb) in the solution made the film smoother and improved the film crystallinity. This enhanced the PCE to about 13~15%. However, for films derived from solution with low Pb(OAc)2/MAI or high Pb(OAc)2/MAI ratios, defects such as pits or pinholes were easily formed, with low crystallinity. These decreased the lifetime of the carriers and thephotoelectrical properties of the final solar cells.