Photovoltaic Recovery of All Printable Mesoporous-Carbon-based Perovskite Solar Cells

Lead halide perovskites attract much attention in recent years as a realistic solution for efficient and low-cost solar cells. One of the interesting solar cell structures is the fully mesoporous-carbon-based perovskite solar cells. The mesoporous layers can be fabricated entirely by screen printing with the potential for upscaling. Herein, the two-step deposition of perovskite in mesoporous-carbon-based perovskite solar cells is studied. The influence of the dipping time on the photovoltaic parameters is investigated using charge extraction and intensity-modulated photovoltage spectroscopy (IMVS) measurements. A power conversion efficiency of 15% is observed for cells fabricated using two-step deposition which is one of the highest reported for this solar cell structure. Stability characterizations at maximum power point (MPP) tracking show degradation with time, however a complete recovery of the devices in the dark is revealed. Analyzing the mechanism for this shows that the perovskite's unit cell shrinks during the recovery process due to internal stress relief. This interesting phenomenon opens the possibility to optimize the stability of these solar cells for commercial applications.