Bending Durable and Recyclable Mesostructured Perovskite Solar Cells Based on Superaligned ZnO Nanorod Electrode

Though high-quality perovskite films can be achieved under low-temperature, the efficient charge selective materials, such as the most widely used TiO₂, require high-temperature sintering process, hindering mass production with roll-to-roll process by using flexible substrate. Here, a low-temperature (90 °C) process is developed for preparing superaligned ZnO nanorods (SAZNRs), serving as mesostructured scaffold in direct contact with the perovskite layer. By rational design of the length of the SAZNRs, the perovskite solar cell (PSC), reaches a highest power conversion efficiency of ≈13.8% with largely suppressed hysteresis behavior. More importantly, this nano-array design demonstrates outstanding mechanical robustness after being incorporated onto the flexible substrate, resulting in a performance preservation of 90% after 1000 bending cycles with a curvature radius of 4 mm. Finite element analysis indicate that the reduction of device performance after bending is ascribed to the cracks occurred in AZO stress concentration layer, which is attested by experiment as well. Besides, the SAZNRs ETM can be reused for fabricating new perovskite solar cells with comparable photovoltaic performance in a time-saving and scalable manner, paving the way for industrial production of PSCs.