Carbon Dot‐Supported Single‐Atom Materials Boost the Efficiency and Stability of Inverted Perovskite Solar Cells

Abstract Buried interface engineering is a promising approach to tackling the comprehensive issue in inverted organic‐inorganic perovskite solar cells (PVSCs). Carbon dots have fascinating photo‐electronic properties, which could be precisely tailored by doping with metal single‐atoms. Here, the utilization of carbon‐dots supported Cu single‐atom materials (Cu‐CDs) as the interlayer between hole‐transporting and perovskite layers of inverted PVSCs is reported, which resulted in a substantial improvement in photovoltaic performance and a significant enhancement in both UV‐light resistance and long‐term stability. The optimal device holds a power conversion efficiency of up to 25.35% with good stability, resulting from the diverse interaction between Cu‐CDs and perovskites, particularly the formation of the Cu‐I bonds confirmed by the synchrotron‐based X‐ray absorption spectroscopy and density functional theory calculations. These findings unveil the interaction between Cu‐CDs and the perovskite layer and offer a promising strategy for the buried interface engineering of PVSCs.