Unraveling the Degradation Pathway of Inverted Perovskite Solar Cells Based on ISOS-D-1 Protocol

Perovskite solar cells (PSCs) have shown rapid development recently, whereas nonideal stability remains the chief obstacle toward commercialization. Thus, it is of utmost importance to probe the degradation pathway for the entire device. Here, the extrinsic stability of inverted PSCs (IPSCs) is investigated by using standard shelf-life testing based on the International Summit on Organic Photovoltaic Stability protocols (ISOS-D-1). During the long-term assessment of 1700 h, the degraded power conversion efficiency is mainly caused by the fill factor (53% retention) and short-circuit current density (71% retention), while the open-circuit voltage still maintains 97% of the initial values. Further absorbance evolution and density functional theory calculations disclose that the perovskite rear-contact side, in particular for the perovskite/fullerene interface, is the predominant degradation pathway. This study contributes to understanding the aging mechanism and enhancing the durability of IPSCs for future applications.

Automated summary

In order to understand the degradation pathway of perovskite solar cells (PSCs), an investigation on the extrinsic stability of inverted PSCs (IPSCs) was conducted. The long-term assessment revealed that the degraded power conversion efficiency was mainly caused by the fill factor and short-circuit current density, while the open-circuit voltage remained relatively stable. Absorbance evolution and density functional theory calculations further identified the perovskite rear-contact side, particularly the perovskite/fullerene interface, as the predominant degradation pathway. This study contributes to a better understanding of the aging mechanism and paves the way for enhanced durability of IPSCs in future applications.