Effect of mild mechanical stresses on device physics of slot-die coated flexible perovskite solar cells

Halide perovskites are a promising class of novel photoactive materials for their application in flexible photovoltaic devices. Tolerance and stability of devices to various mechanical stresses are important aspects of this technology for its effective and long-term operation. Currently, this aspect has not been fully researched and addressed by the research community. Hence, this work is aimed at studying the effect of mild mechanical stresses (MMSs) induced by convex bending on the behaviour of ITO/ZnO/MAPbI₃/Spiro-OMeTAD/Au slot-die-coated flexible perovskite solar cells (FPSCs) and investigating the underlying mechanisms leading to performance degradation in devices. The carrier generation, recombination, and extraction processes within FPSCs are investigated before and after the application of MMSs. The obtained results suggest that the photovoltaic performance of the FPSCs deteriorates by up to 50% after convex bending, due to increased non-radiative recombination losses. The results obtained in this work provide some valuable insights into the dynamics of recombination processes in FPSCs exposed to MMSs and can be used for developing new strategies for improving the mechanical stability of devices.