A-D-A Molecule-Bridge Interface for Efficient Perovskite Solar Cells and Modules

As the photovoltaic field endeavors to transition perovskite solar cells (PSCs) to industrial applications, inverted PSCs, which incorporate fullerene as electron transport layers, have emerged as a compelling choice due to their augmented stability and cost-effectiveness. However, these attributes suffer from performance issues stemming from suboptimal electrical characteristics at the perovskite/fullerene interface. To surmount these hurdles, an interface bridging strategy (IBS) is proposed to attenuate the interface energy loss and enhance the interfacial stability by designing a series of A-D-A type perylene monoimide (PMI) derivatives with multifaceted advantages. In addition to passivating defects, the IBS plays a crucial role in facilitating the binding between perovskite and fullerene, thereby enhancing interface coupling and importantly, improving the formation of fullerene films. The PMI derivatives, functioning as bridges, serve as a protective barrier to enhance the device stability. Consequently, the IBS enables a remarkable efficiency of 24.62% for lab-scale PSCs and an efficiency of 18.73% for perovskite solar modules craft on 156 × 156 mm² substrates. The obtained efficiencies represent some of the highest recorded for fullerene-based devices, showcasing significant progress in designing interfacial molecules at the perovskite/fullerene interface and offering a promising path to enhance the commercial viability of PSCs.