Stability of Inverted Perovskite Solar Cells: a focus on interface phenomena

Abstract

The so-called inverted perovskite solar cells (PSCs), with a p-i-n device architecture have recently outperformed the traditional n-i-p counterparts in terms of record power conversion efficiency (PCE). The design of their interfaces has emerged as the key driver of PCE improvements. Said this, it has been soon very clear that it was also a critical point in defying the device stability. This review provides a comprehensive overview of degradation mechanisms especially related to interface phenomena and with a special focus on the role of defects. Beginning with an analysis of the intrinsic instability issues of pristine interfacial materials, it will move to the interface-induced instability in perovskite absorber, including chemically driven degradation, defect and phase impurities, ion accumulation and migration, and mechanical delamination. Eventually, it is offered an updated review of approaches to mitigate the instability caused by interfaces limitations, including controllable surface construction, multi-layer interface, and stable transport layer design. Future research directions are proposed to guide the development of durable inverted PSCs toward real-world applications.