A review of photostability in organic solar cells: from mechanisms to improvement strategies

Abstract

Organic solar cells (OSCs) represent a promising emerging low-cost thin-film photovoltaic technology. The emergence of non-fullerene small molecule acceptors has reinvigorated the OSC field, leading to significant breakthroughs in their power conversion efficiencies (PCEs). However, the instability and degradation of materials and devices, especially photoinstability, severely limit their commercial applications and, thus, need more attention. This review first analyzes the photodegradation mechanisms of OSCs under different conditions to explore the factors influencing photostability from materials to devices. Then, we highlight recent progress in strategies to improve the photostability of OSCs, including material design and device engineering. Finally, an outlook toward more photostable OSCs is proposed. Coordinating the required device stability and efficiency would provide a possible way to facilitate the viable commercialization of OSCs.