Electrodeposited Self-assembled Monolayers for Improving the Efficiency and Stability of Perovskite Solar Cells

Preventing self-assembled monolayers (SAMs) detachment and enhancing their passivation effect on perovskites are critical challenges for improving the performance and stability of perovskite solar cells (PSCs). Electrodeposited SAMs offer a versatile approach for achieving uniform coverage and robust adhesion on conductive substrates, which is superior to the conventionally solution-processed SAMs. Here, we demonstrate a combinatorial concept of electrodeposited SAMs with tailored functional groups by simply applying electric potentials. The electrodeposited SAMs promote molecular rearrangement, diffusion, and re-anchoring, resulting in a uniform and dense functional layer onto indium tin oxide (ITO) substrate. Building on this base SAM, functional units are grown via electrochemical oxidative coupling, forming tailored coupled carbazole phosphonic SAMs. PSCs incorporating the electrodeposited SAMs exhibit a promisingly high efficiency of 26.8% as well as excellent device stability under one sun illumination at 65 °C for 2500 hours.