LAUSR

Abstract Recent years have witnessed a significant performance breakthrough in both metal halide perovskite (MHP) solar cells and light-emitting diodes, but their unsatisfactory operating stabilities are still the main challenges toward commercialization. We have summarized different kinds of organic species including organic cations in MHP crystal, functional molecules in MHP polycrystalline bulk films, ligands attached on MHP quantum dots, covered polymers in composite films and encapsulants coated on devices. They assume key roles in film formation, stabilizing black phase, passivating defects, extending photoluminescence lifetime, inhibiting charge-recombination and preventing degradation. This review further examines the relationship among crystal structure, optical and electrical properties, performance and stability, revealing several irreplaceable roles of organic species in determining the performance and stability of MHP devices. Finally, we call on establishing standard stability measurements and exploring efficient encapsulation methods to improve the stabilities of MHP solar cells and LEDs, which pushes them from a promise to a production and promotes a continuous progress in this field.