Unveiling the Myths of Co‐Deposition of Hole Conductors and Perovskite Layers

Abstract Perovskite solar cells (PSCs) hold great promise as photovoltaic technology, with power conversion efficiencies exceeding 27%. To further reduce the levelized cost of energy, simplifying PSC manufacturing processes is essential. In this study, a streamlined one‐step solution‐coating strategy is introduced that simultaneously deposits both the hole‐conductor and perovskite layers. It is demonstrated that doped self‐assembled monolayers (SAMs), containing phosphonic or carboxylic acids, diffuse and spontaneously assemble on both indium tin oxide (ITO) substrates and perovskite surfaces during film formation. This process results in a stable monolayer that functions as an efficient hole‐selective contact while promoting favorable perovskite crystallization. Moreover, the incorporation of a functional isolation layer effectively mitigates the side effects induced by perovskite‐anchored SAMs, thereby enhancing device efficiency and stability. The resulting PSCs exhibit a remarkable power conversion efficiency of 25.1% and maintain over 85% of their initial performance after 1000 h of maximum power point tracking under continuous illumination.