Effects of molecular conformation on buried interface passivation and efficient perovskite solar cell realization employing fluorine substituted benzoic acid

Benzoic acid containing fluorine atom at ortho-, meta-, and para-position are employed as self-assembled monolayers to modify the buried interface in perovskite solar cells (PSCs). It is demonstrated that the position of fluorine atom influences the passivation effect and para-fluorinated one provided the most substantial performance enhancement mainly originating from ameliorated contact and energy band alignment between NiO_x and perovskite, improved perovskite quality and defect healing. Resultantly, PSC with a power conversion efficiency of 24 % can be achieved. Meanwhile, which can maintain 96.8 % of the initial PCE after a 1000 h storage, presenting enhanced durability. This work highlights the critical role of molecular functionality and conformation in the buried interface modification of PSCs, providing valuable insights for future developments.