Flexible perovskite solar cells with ultrathin Au anode and vapour-deposited perovskite film

Flexible perovskite solar cells (pero-SCs) possessing high efficiency and low fabrication cost have been considered as the promising wearable energy supply devices in the near future. However, the intrinsic brittleness of the commonly used transparent conducting oxide electrodes is one of the limitations for the mechanical stability of flexible pero-SCs. Here we demonstrate the improved mechanical stability of flexible pero-SCs consisting of ultrathin Au electrode and vapour-deposited perovskite film. The thermal annealing-free perovskite film fabrication by vapour deposition is beneficial to the stability of the ultrathin Au electrode and contributes to the improved mechanical stability of the flexible pero-SCs. The power conversion efficiency for flexible pero-SCs maintains 74% of their initial efficiencies after 2000 bending cycles with a bending radius of 3.5 mm.