An efficient cyclopenta[hi]aceanthrylene-based D–A–D type dopant-free hole transport material termed YN3 showed impressive PCEs of 18.84% and 12.05% with very good stability in organic–inorganic hybrid and all-inorganic perovskite solar cells, respectively.

Two indacenodithiophene-based HTMs have been designed and applied in PSCs. The PSC device based on YK1 displays a very impressive PCE of 20.13%.

Two fluorene-based HTMs have been synthesized for use in perovskite solar cells (PSCs). The (FAPbI3)0.85(MAPbBr3)0.15 and CsPbI2Br PSCs devices based on YT3 yield very impressive PCEs of 20.23% and 13.36%, respectively.