Flexible Perovskite Solar Cells onto Plastic Substrate Exceeding 13% Efficiency Owing to the Optimization of CH3NH3PbI3–xClx Film via H2O Additive

In this work, flexible perovskite solar cells (F-PSCs) are fabricated utilizing the device polyethylene terephthalate (PET) substrate/ITO/PEDOT:PSS/CH3NH3PbI3–xClx/PCBM/Ag, which exhibits the optimal power conversion efficiency (PCE) reaching 13.27%, superb stability against bending deformation, and advantageous stability in ambient atmosphere without encapsulation. Meanwhile, we herein confirm a fact that incorporating suitable H2O additive into the perovskite precursor solution leads to an enhanced CH3NH3PbI3–xClx perovskite quality for F-PSCs application, including the improvement of morphology and electrical properties. To better summarize the mechanism concerning how H2O additive affects the perovskite film quality, CH3NH3PbI3–xClx films are prepared by a simple one-step spinning method from a solution containing CH3NH3I, PbI2, and PbCl2 in a mixed solvent of H2O and dimethylformamide (DMF) with solely various volume ratio ranging from 0.1% to 0.9%. Through a comparative analysis, it is proposed that...