Turning copper into gold: cost-effective positive electrodes for high-performance perovskite solar cells

Abstract

Abstract The development of cost-effective metal electrodes is essential to reduce the overall cost of perovskite solar cells (PSCs). Copper stands out as a highly conductive and cost-effective material, but has been seldomly used as positive electrodes in efficient n-i-p PSCs due to its small work function and low oxidation threshold. We report herein that surface engineering with mercaptopyridine-based molecules readily endows copper with gold-like electronic and chemical properties. Appropriate electronic structure of copper can be achieved by fine-tuning the substituents of mercaptopyridines, making the modified copper electrodes applicable in PSCs with different hole transport materials. The resulting PSCs with copper electrodes display high power conversion efficiency, excellent long-term stability, and dramatically enhanced oxidation resistance, comparable to the gold counterparts. The cost-effective copper electrodes show great potential in manufacture and commercialization of PSCs.