Perspectives on the mechanical robustness of flexible perovskite solar cells

Abstract

Flexible perovskite solar cells (FPSCs) show promise for future applications in wearable electronic devices, biosoft robots, and advanced sensors due to their high power-conversion efficiency, low manufacturing cost, and high flexibility. The inevitable performance degradation during long-term service is the major challenge for the commercialization of perovskite solar cells. Mechanical robustness, which is the stability of PSCs under large deformation and high-number cyclic loading, is of particular concern for FPSCs. Numerous strategies have been proposed to improve the mechanical robustness by enhancing the inherent toughness of the major components, relieving stress by optimizing the structure of the device, and developing high-quality film fabrication methods. FPSCs are not as mechanically robust as other types of flexible cells, and the coupled mechanical–optoelectronic degradation mechanism for FPSCs and the associated experimental and theoretical methods require further investigation. This perspective highlights recent advances in improving the mechanical robustness of FPSCs with respect to internal and external structural optimization and the influence of mechanical deformation on photovoltaic behavior. Current challenges and future perspectives for clarifying the qualitative mechanism between the mechanical behavior and the photovoltaic performance as well as establishing quantitative descriptions of the mechanical robustness are elaborated, aiming to provide more scientific and practical guidance for the design of FPSCs with high efficiency and robustness.