Selecting non-halogenated low-toxic hole transporting materials for Roll-to-Roll perovskite solar cells using carbon electrodes

Abstract Perovskite solar cells hold promise for cost-effective, high-efficiency renewable energy generation; yet their commercialization is hindered by progress towards scalable fabrication methods. Roll-to-roll processing is a promising solution for large-scale production, and the incorporation of Roll-to-roll coated carbon electrodes offers several additional advantages, including low-cost manufacturing and high-stability. Introducing a compatible hole transporting layer between perovskite and carbon significantly improves performance. Here we present a study comparing four interlayers (Spiro-MeOTAD, PTAA, PEDOT, and P3HT) in printed devices, assessing efficiency, stability, and scalability. Our results reveal that spiro-MeOTAD and PTAA was not compatible with the carbon electrode however PEDOT and P3HT showed promising results. Beyond photovoltaic performance, comparison of P3HT and PEDOT in terms of stability, toxicity, and cost reveals that P3HT can be a superior choice for scaling up manufacturing. These findings offer valuable insights for optimizing perovskite solar cells performance in scalable production via roll-to-roll printing.