Enhancing Mechanical Stability and Performance of Perovskite Solar Modules With MXene Interface Adhesives

Perovskite solar modules feature inherently soft interfacial mechanical properties, making them more prone to failure than silicon-based devices. The lattice mismatch between perovskite absorbers and π-conjugated hole transport materials (HTMs) severely weakens adhesion and stability but remains insufficiently studied. Here, iodide-capped Ti₃C₂T_x MXene is synthesized and employed as a "bone-joint" interfacial modulator to bridge perovskite and a π-conjugated phthalocyanine HTM. Iodide terminals coordinate strongly with surface Pb²⁺ ions, while the π-conjugated basal plane forms π-π interactions with phthalocyanine, creating dual binding that enhances adhesion and relieves residual stress. Mechanical tests-including free-fall impact, tape peeling, and bending-confirm substantially improved robustness. This dual interaction also optimizes energy-level alignment at the perovskite/phthalocyanine interface, while the incorporation of conductive Ti₃C₂T_x at the HTM/electrode interface enhances charge extraction, enabling the perovskite module with an active area of 21.54 cm² to achieve an efficiency of 22.51%-among the highest reported for such systems. This work demonstrates an effective interfacial strategy for enhancing both mechanical stability and performance, advancing the practical application of perovskite photovoltaics.