Degradation of Polymer Solar Cells: Knowledge Learned from the Polymer:Fullerene Solar Cells

Abstract

Although power conversion efficiency (PCE) of polymer solar cells (PSCs) has exceeded 18%, the lifetime of PSCs is far away from satisfactory and has become the most critical issue before the commercialization of PSCs. Understanding the degradation mechanism and finding the proper way to suppress the degradation process are of high interests for PSC research. Polymer:fullerene solar cells (PFSCs) have a long research history and the working principle is well‐understood, so they are good models for the degradation mechanism study. This mini‐review summarizes the latest research progress of the PFSCs’ degradation studies. Based on the results achieved, one can identify the extrinsic and intrinsic stress factors that cause different degradation processes. Degradation pathways of the PFSCs at different positions in the cells will be discussed in detail, including the electrode, the buffer layer, and the photoactive layer. Special emphasis will be put on various degradation processes of the photoactive layers. In the meantime, the methods to suppress the degradation processes will be presented accordingly. This mini‐review gives a comprehensive insight into the degradation mechanism and stability‐improvement strategies of PFSCs, which has important guiding significance for the stability‐improvement research of PSCs.