Search

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/MAPbI 3 /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. [Display omitted] • Flexible perovskite solar cells fabricated by a slot-die coating method. • A comprehensive analysis of the device physics of flexible slot-die-coated perovskite SCs. • Unravelling device physics of slot-die-coated flexible PSCs before and after applying mild mechanical stresses. [ABSTRACT FROM AUTHOR]

Morphological homogeneity and interfacial traps are essential issues to achieve high-efficiency and stable large-area organic solar cells (OSCs). Herein, by the investigation of three quinoxaline-based acceptors, i.e., PM6:Qx-1, PM6:Qx-2, and PM6:Qx-p-4Cl, the performance degradation in up-scaling OSCs is explored. The inhomogeneous morphology in PM6:Qx-2 induces a nonuniform spatial distribution of charge generation, showing a rapid decline in efficiency and stability in large-area OSCs. In comparison, the homogeneous morphology in PM6:Qx-1 and PM6:Qx-p-4Cl alleviates the stability drop. When utilizing 2-phenylethylmercaptan to fill the interfacial traps, the stability drop disappears for PM6:Qx-1 and PM6:Qx-p-4Cl, while it persists for PM6:Qx-2. The PM6:Qx-1 large-are device yields a high efficiency of 13.47% and superior thermal stability (T 80 = 2888 h). Consequently, the interface modification dominates the performance degradation of large-area devices with homogeneous morphology, while it cannot eliminate the traps in inhomogeneous film. These results provide a clear understanding of degradation mechanisms in upscaling devices., (© 2024 Wiley‐VCH GmbH.)

• Diglycolic acid (DA) was introduced as an efficient additive for better slot-die-coated perovskite production. • 14.63% efficiency was obtained in slot-die-coated perovskite solar cells with DA. • DA based PeSCs showed superior long-term stability under ambient conditions. In slot-die-coating process, novel approaches for better perovskite film formation were continuously required. Here, we studied additive processes for better slot-die-processed perovskite fabrication. ​As a novel additive, we introduced diglycolic acid (DA) material having a carboxyl group, well known as an effective functional group. With adding optimal amount of DA in the perovskite precursor solution, device efficiency and stability were all improved; DA-based perovskite device showed the best PCE of 14.63%. Moreover, the DA-based devices showed superior long-term stability guaranteeing 80% of initial efficiency during 95 days. [ABSTRACT FROM AUTHOR]