Ion Migration in Halide Perovskites

Halide perovskites have opened a new world for several scientific communities by their intriguing semiconducting properties and merits in solution processing. For photovoltaic applications, remarkable success in developing high power conversion efficiency and large area perovskite solar cells (PSCs) has been achieved in the past decade, demonstrating their huge potential in commercialization. So far, the operation lifetimes of PSCs are still needed to be improved. One challenge for the long-lifetime device is the presence of ion migration in halide perovskites. The easy ion migration results in mobile point defects in crystals and accelerates the degradation of perovskite materials, which cannot be rooted out by device encapsulation. Strategies for suppressing ion migration effect are therefore crucial from this point of view. In this chapter, the general knowledge and some updated insights about the ion migration effect in perovskites will be introduced.