<p>Self-assembled monolayers (SAMs) play an important role in improving the performance of inverted perovskite solar cells. However, loose molecular packing, non-uniform coverage, weak affinity with the solvents of perovskite precursors, and energy-level mismatch cause energy losses at the buried interface. Here we develop a light-stable donor–acceptor interface formed by an asymmetric carbazole-based SAM, namely, BrAs, and <i>N</i>-hydroxyethyl phthalimide (PIE). The single-side electron-withdrawing bromine in BrAs maintains wettability and reduces the valence band offset to 0.09 eV. Additionally, the asymmetric dipole in BrAs reorients the carbazole units and strengthens short-range Coulomb interactions, resulting in close packing and uniform coverage of SAMs for efficient and uniform carrier transport. The donor–acceptor interface also promotes ultrafast energy transfer, which enhances the photostability of BrAs and improves thermal carrier extraction by 19%, further minimizing energy losses. In particular, the lattice-matching PIE molecules stabilize the (100) out-of-plane orientation of the perovskite by interlocking [PbI₆]^4⁻ octahedra, which releases compressive stress and stabilizes the buried interface. As a result, BrAs–PIE devices achieve a power conversion efficiency of 27.28% (certified, 27.19%) and retain over 95% of the initial efficiency after 1,500 h of illumination under the ISOS-L-2 protocol.</p>