Flexible Cu₂AgBiI₆-based perovskite-inspired solar cells using large-scale processing methods

Abstract

In this work, emerging perovskite-inspired Cu2AgBiI6 (CABI) solar cells were successfully fabricated on flexible substrates, demonstrating that the transition from rigid to flexible materials does not compromise device performance. This underscores the versatility of CABI on two different kinds of substrates. Additionally, to optimize charge extraction, we selected a polymeric hole-transport material (HTM), PPDT2FBT, whose energy levels align with CABI. The PPDT2FBT-based devices outperformed those using the well-known poly(3-hexylthiophene) (P3HT), leading to power conversion efficiencies as high as approximately 0.8%. These results suggest that PPDT2FBT may hold promise as a HTM for use in low-toxicity, perovskite-inspired photovoltaic systems, such as those based on CABI. Furthermore, roll-to-roll processing techniques, crucial for scalable production, were tested. However, controlling the morphology of the active layer remains a significant challenge. These findings represent critical steps toward the large-scale manufacturing and commercialization of flexible, PIM-based solar cells.