Synergistic Integration of Two-Dimensional Materials and Perovskites for Next-Generation Solar Cells

Abstract The integration of two-dimensional (2D) materials with metal halide perovskites offers a multidimensional approach for simultaneously addressing the interfacial, electronic, ionic, and stability-related limitations of conventional perovskite solar cells. Despite demonstrating the power conversion efficiencies of over 26%, their practical commercialization remains hindered by factors such as severe environmental instability, ion migration, interfacial recombination, and thermal degradation. Recent studies demonstrate that graphene, transition metal dichalcogenides (TMDs), MXenes, layered 2D perovskites, and related architectures can modify charge transfer, interfacial energetics, defect populations, crystallization behavior, and ionic transport through cooperative interfacial effects. This review highlights the recent progress in multidimensional 2D-perovskite heterostructures by focusing on interfacial engineering, charge-transfer dynamics, defect passivation mechanisms, and performance-enhancement pathways. There is particular emphasis on graphene-assisted transport layers, TMD-based heterointerfaces, MXene-enabled architectures, graded quasi-2D systems, and van der Waals (vdW) heterostructures. Furthermore, the review also addresses the challenges associated with synthesizing these solar cells, such as scalability, phase instability, interfacial reconstruction, and long-term reliability under operational conditions. The review concludes by discussing promising opportunities in flexible photovoltaics, tandem solar cells, and multifunctional optoelectronic systems. Collectively, synergistic 2D-perovskite heterostructures exhibit a promising route to more efficient, stable, and commercially viable next-generation solar-energy technologies. This review integrates material-specific architectures with their underlying physicochemical mechanisms, enabling a comparative assessment of interfacial engineering, charge-transfer pathways, defect regulation, ion migration, crystallization, and device stability across different 2D-perovskite systems.