Manipulating Perovskite Precursor Solidification Toward 21% Pristine Mapbi(3) Solar Cells

Controlling the crystallization of perovskite film is critical for high-performance perovskite solar cells (PVSCs), and temperature is the key factor dominating the nucleation and crystal growth. Herein, it is demonstrated that the inconspicuous ambient temperature plays an important role in reaching high-quality perovskite film and high-performance PVSCs. It is observed that the ambient temperature greatly affects the composition of as-prepared perovskite film, which dramatically influences the perovskite film morphology during the subsequent annealing process. Remarkably, the device prepared at the optimal ambient temperature of 29 degrees C exhibits the best power conversion efficiency of 20.91% with little hysteresis. This represents one of the best results for inverted PVSCs based on pristine MAPbI(3) system. In addition, the PVSC prepared at 29 degrees C shows good stability with 80% of its initial efficiency after 30d in air with a humidity of 45%. Overall, the importance of ambient temperature for crystallization of the perovskite film is emphasized, and this work should have implications for controlling the morphology for high-performance PVSCs.