Carbon‐Based Materials in Perovskite Solar Cells: Electrodes, Charge Transport Layers, and Interlayers

Carbon‐based materials provide transformative solutions to address the key challenges of cost, stability, and scalability in perovskite solar cells (PSCs). This review explores the diverse roles of carbon‐based materials (including graphite, carbon black, carbon nanotubes, graphene derivatives, fullerene derivatives, and carbon quantum dots) as high‐performance alternatives in functional layers. As electrodes, carbon‐based materials replace costly noble metals while providing high chemical stability, hydrophobicity, and mechanical flexibility, thereby enhancing device stability under harsh thermal and humid conditions. For charge transport layers, the incorporation of carbon‐based materials improves carrier mobility, suppresses trap‐assisted recombination, and optimizes Interfacial energy band alignment. Additionally, the carbon‐based intermediate layer effectively promotes charge extraction, passivates interface defects, and improves interface contact. The compatibility of carbon‐based materials with low‐temperature solution‐processing techniques highlights their potential for large‐scale production. This review assesses the state‐of‐the‐art, material design strategies, and performance of carbon‐based PSCs, and outlines future directions toward high‐efficiency, stable, and commercially viable devices.