Metal chalcogenide nanostructures: A bifunctional platform to resolve the efficiency-stability trade-off in commercial perovskite solar cells

Methylammonium lead iodide (MAPbI₃) perovskite solar cells (PSCs) have achieved certified power conversion efficiencies (PCEs) approaching 24 % (with alloyed variants exceeding 26 %), rivaling established photovoltaic technologies. However, their path to commercialization is blocked by a persistent "defect-stability double bind": reversible defects (e.g., iodine vacancies, undercoordinated Pb²⁺) cause non-radiative recombination and performance variability, while environmental instability leads to rapid degradation under moisture, light, and heat. Current passivation strategies, including organic molecules, 2D perovskites, and alkali doping, invariably sacrifice one key parameter for another. This perspective articulates a transformative solution: the integration of metal chalcogenide nanostructures (e.g., ZnSe, MoSe₂) as a versatile, bifunctional platform. We synthesize experimental and computational evidence demonstrating that these materials simultaneously passivate defects through strong chalcogenide-Pb²⁺ coordination and provide robust environmental shielding via nanostructured barriers. For instance , champion ZnSe-doped MAPbI₃ devices achieve a PCE of 23.1 % (a 12.7 % improvement) and a 3.5 × increase in operational lifetime (T80 = 520 h ). Critically, this approach is scalable and cost-effective, with material costs as low as $15–30/g. We further project that this platform can unlock PCEs beyond 27 % and lifetimes exceeding 1000 h, while also enabling high-performance tandem cells and reducing lead leakage. By fundamentally resolving the efficiency-stability trade-off, metal chalcogenide nanostructures are positioned as a cornerstone technology for the commercialization of next-generation perovskite photovoltaics. • Metal chalcogenides may fix perovskite solar cells' core flaw. • They may boost efficiency to 23.1 % and extend lifetime by 3.5x. • This may solve the critical efficiency-stability trade-off. • They are potentially low-cost ($15–30/g) and scalable. • The material may reduce toxic lead leakage by 70 %.