Lead Oxalate-Induced Nucleation Retardation for High-Performance Indoor and Outdoor Perovskite Photovoltaics

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.