A non-fullerene acceptor as an interfacial modified layer for enhancing efficiency and stability of inverted perovskite solar cells

With the rapid development in the advanced research of perovskite solar cells (PSCs), the regulation of perovskite crystallinity and defect states has become increasingly crucial to further enhance the performance of PSCs. Here, we introduced a novel non-fullerene acceptor (NFA) material, INDCDT-b8-Cl, as an ultra-thin interfacial modified layer (IML) to optimize the quality of the perovskite active layer by passivating surface, reducing defects and grain boundaries. As a result, the optimized PSCs exhibited excellent PCE, VOC and FF. Furthermore, the optimized PSCs with NFA IML show an outstanding stability compared to the control devices under the same working conditions. This work provides a facile method to tune the crystallization and reduce the defects to improve the performance of PSCs. The molecular structure of INDCDT-b8-Cl, which is rich in carbonyl and cyano functional groups, is used as an interfacial modified layer for PSCs.