Influence of Perovskite layer Sequential Deposition on the Self-Assembled Monolayer in Inverted Perovskite Solar Cells

Perovskite solar cells (PSCs) have gained significant attention in the energy sector due to their rapid advancements. Inverted PSCs, known for their compatibility with low-temperature processing and tandem cell integration, have been a focal point of research, particularly with self-assembled monolayers (SAMs) employed as the hole transport layer (HTL). , However, the sequential spin-coating method, involving PbI2 deposition followed by an organic halide layer to form the perovskite film, poses challenges for SAMs-based HTLs, as the repeated exposure to polar solvents can disrupt the SAMs and the detached SAM molecules may agglomerate randomly during perovskite crystallization, which further hindering charge transport and increasing leakage current. In this study, we fabricated SAM-based devices with varying spin coating processes followed by morphological and structural characterizations. Our results indicate that SAM-HTLs devices have better performance when using one-step spin coating process, while two-step method yields larger perovskite crystals in SEM but their show a differed crystal orientation than the device without SAMs. This study elucidates the effects of perovskite film coating methods on SAM materials, and suggests practical strategies for improving the performance and stability of SAM-based inverted PSCs.