Non‐Fullerene Organic Electron‐Transporting Materials for Perovskite Solar Cells

Abstract Organic electron‐transporting materials (ETMs) with low‐temperature solution processability and high electron‐transfer/transport characteristics have received significant attention for their use in high‐performance perovskite solar cells (PSCs). In contrast to widely investigated fullerene‐based organic ETMs for PSCs, only a few types of non‐fullerene‐based ETMs have been developed. In this Concept article, a representative design concept for non‐fullerene ETMs is described for use in normal (n‐i‐p) and inverted (p‐i‐n) type PSCs. On the basis of a discussion on ETM requirements for PSCs, recently developed non‐fullerene polymeric and small‐molecule‐based ETMs for PSCs are highlighted, alongside various other approaches for enhancing PSC device performance, such as using additional dopants and introducing amine terminal groups in the ETMs and ETM‐based interlayers. This Concept provides a basic design concept for non‐fullerene‐based ETMs in PSCs.