Perovskite Heterostructures for Optoelectronic Applications.

Perovskite heterostructures, which integrate two or more functional materials into one coupled system, have emerged as an important strategy for stabilizing perovskite materials and enabling high-performance optoelectronic devices. Through rational design of composition and interfaces, these heterostructures can reduce defect density, suppress ion migration, relieve structural strain, and improve resistance to moisture, heat, and light. They can also combine the complementary advantages of different components in structural and optoelectronic properties. These features give perovskite heterostructures clear benefits for both material stability and device operation. In solar cells, they enhance interfacial stability and device durability, while supporting efficient charge extraction. In light-emitting diodes, they help maintain phase and emission stability, suppress non-radiative losses, and extend operational lifetime. In this Review, we summarize recent advances in the design, compositional engineering, interfacial mechanisms, and optoelectronic applications of perovskite heterostructures. We also discuss the key challenges and future directions in this field.