Fluorination of Star‐Shaped Cyclopenta[2,1‐b;3,4‐b′]dithiophene Derivatives and Its Application as Hole‐Transporting Materials in Scalable Perovskite Solar Cell Fabrication by Bar Coating

Perovskite Solar Cells In article number 2300988, Lee, Hsieh, Lu, Lin, and co‐workers synthesized three star‐shaped cyclopentadithiophene derivatives, with or without fluorine atoms incorporated, and applied them as hole‐transporting materials in the fully scalable fabrication of perovskite solar cells (PSCs) using the thermal‐assisted bar‐coating method. The PSCs fabricated from such films delivered a high power conversion efficiency of 18.49% on a large scale with encouraging long‐term stability.