Fully-ambient-air and antisolvent-free-processed stable perovskite solar cells with perovskite-based composites and interface engineering

For commercialization of perovskite solar cells (PSCs), the device stability issues attributed to degradation of perovskite material, photo and thermal instability, and photocurrent density-voltage (J-V) hysteresis behavior should be solved. Furthermore, most of presented high efficiency PSCs utilize an antisolvent-strategy to assist perovskite crystal growth with large grain-size and excellent coverage. To solve such issues, we developed fully-ambient-air and antisolvent-free processes for the fabrication of PSCs with perovskite-based composites (i.e., MAPbI_3-xCl_x-Cu:NiO, MAPbI_3-xCl_x-Cu:NiO-carbon-graphite and MAPbI_3-xCl_x-Al₂O₃). Such perovskite composites based cells with interface engineering yielded high power-conversion-efficiency (PCE) of 18.6% and fill factor (FF) of 78.3% with excellent reproducibility. More importantly, the target cells showed hysteresis-free behavior and dramatic enhancement in air-, photo- and thermal-stability. Compared to the pristine cells, the target device showed remarkable long-term stability with retaining almost 100% of the initial values of V_oc and J_sc, and ~94% of FF and PCE over 280 days.