摘要： Perovskite solar cells have attracted worldwide attention as one of the key research areas in the field of thin film photovoltaics. Although, they exhibit easy solution-processability, it is important to effectively control the crystallization of the light absorbing layer which affects the performance and stability of devices. Here, we present lead oxalate (PbC2O4) as a non-halide lead constituent of the perovskite precursor solution, which contributes to anion replacement during thin film annealing. This strategy limits the perovskite nucleation rate and retards crystallization. As a result, we achieved excellent perovskite film with larger grains and less defects. The open circuit voltage of the optimal device under one sun illumination rose to 1.12 V with a power conversion efficiency (PCE) of 20.20%. In addition, the indoor PCE at 1000 lux can reach 34.86%. This non-halide lead compound dopant provides a guide on the crystallization of perovskite materials and paves a way for the fabrication of non-halide perovskite solar cells.