Cyclopenta[hi]aceanthrylene-based dopant-free hole-transport material for organic–inorganic hybrid and all-inorganic perovskite solar cells

Hole-transport materials (HTMs) play an important role in the most highly performing perovskite solar cells (PSCs). In this work, for the first time, an efficient cyclopenta[hi]aceanthrylene-based dopant-free D-A-D type hole transport material (HTM) YN3 is developed for application in organic–inorganic hybrid and all-inorganic perovskite solar cells (PSCs) with high performance. The (FAPbI3)0.85(MAPbBr3)0.15 and CsPbI2Br PSCs devices based on YN3 as a dopant-free HTM render very impressive PCEs of 18.84% and 12.05%, respectively. The obtained PCE values of YN3-based PSCs outperform most dopant-free HTMs based on small organic molecules reported so far. More encouragingly, the YN3-based PSCs without encapsulation display good long-term stability.