Preventing the detachment of self-assembled molecules (SAMs) and enhancing their passivation effect on perovskites are critical challenges for improving the performance and stability of perovskite solar cells (PSCs)1–3. Electrodeposited SAMs provide a route to improve coverage uniformity and anchoring robustness on conductive substrates beyond the limitations of conventional solution processing. Here, we use potential-cycled electrodeposition to promote molecular rearrangement and re-anchoring of SAMs, resulting in a uniform and dense layer on an indium tin oxide (ITO) substrate with enhanced anchoring capability. Building on this base SAM, functional units are grown via electrochemical oxidative coupling to form tailored coupled carbazole phosphonic SAMs, yielding power conversion efficiencies of 26.8% for lab-scale solar cells and 21.3% for solar modules (65 cm2).