A Cross‐Linked PCBM Interlayer for Efficient and UV‐Stable Methylammonium‐Free Perovskite Solar Cells

Interfacial engineering is crucial for perovskite solar cells (PSCs) to ensure efficient charge carrier transfer, and pivotal for device performances. Herein, a novel cross-linked PCBM (CL-PCBM) interlayer at the perovskite/electron transport layer (ETL) interface of the methylammonium-free PSC device is incorporated. The dimeric PCBM interlayer prepared using a facile UV cross-linking technique concurrently improves the quality of the resultant perovskite film and the charge transfer capability of the ETL, leading to significantly enhanced device photovoltaic performances. In addition, the PSC devices integrating the CL-PCBM interlayers exhibit superior humidity and UV stabilities. The successful employment of the CL-PCBM interlayer can bring new insight into the design and engineering of high-quality interfaces for efficient PSCs.