Twisted or Planar? Side-Chain Tailoring of Fluorene-based Hole-Transport Materials for Efficient and Stable Perovskite Solar Cells
The functionalization of small-molecule hole-transport materials (HTMs) heavily relies on the rational design of molecular geometry, which can optimize both intrinsic HTM properties and interfacial properties for realizing high-performance and stable lead halide perovskite solar cells (LHPSCs). Herein, two fluorene-based donor–π linker–donor HTMs are seen, FL01 and FL02, whose side chains are tail