Intrinsic and environmental stability issues of perovskite photovoltaics

Recent years have witnessed the fast development of perovskite photovoltaics and achievement of efficiency increase (now to over 25%). However, stability issues must be satisfactorily dealt with before its real application and commercialization. Environmental stability issues include moisture, oxygen, light, and heat. Moisture was the first recognized stability problem, and has been vastly investigated and successfully strategized in device design and fabrication. Unlike what people believed in the past, light and oxygen do affect the microstructure, electrical and photo-physical properties of perovskites and thus affect stability. Advanced encapsulation techniques might solve some of the stability issues (moisture and oxygen). However, the thermal stability issue has not yet been properly addressed. In addition, the intrinsic molecular dissociation and ion migration inside perovskites are also key issues affecting long-term stability of perovskite photovoltaics. This paper gives a timely review on the recent progress of all these intrinsic and environmental stability issues for perovskite photovoltaics and corresponding possible solutions.