Molecularly Templated Buried Interfaces for Inverted Perovskite Solar Cells

The buried interface between self‐assembled monolayers (SAMs) and perovskite absorbers critically governs charge extraction and stability in inverted perovskite solar cells, yet remains structurally mismatched and poorly controlled. Here, we report a buried‐interface engineering strategy inspired by non‑covalent molecular templating, enabled by complementary triphenylamine‐based molecular building blocks. A triphenylamine‐based ammonium salt, 2‐(4‐(diphenylamino)phenyl)ethanammonium iodide (TPANI), is introduced into the perovskite precursor, while a structurally matched triphenylamine‐based bisphosphonic acid SAM deposited on ITO serves as the hole‐selective layer. Non‐covalent interactions at the buried interface induce molecular templating and interfacial organization of TPANI, strengthening SAM/perovskite adhesion and reducing intergranular groove depth at the buried side of the perovskite film. The resulting monolithically integrated interface suppresses buried interfacial defects, improves energy‐level alignment, and facilitates hole extraction. Consequently, inverted devices achieve a power conversion efficiency of 26.58% with an exceptionally high fill factor of 86.72%, together with markedly enhanced operational stability. These results demonstrate that non‑covalent molecular templating provides an effective and general strategy for engineering buried interfaces in perovskite photovoltaics.