Organic solar cells developments: What’s next?

The research of organic solar cells (OSCs) has made great progress, mainly attributed to the invention of new active layer materials and device engineering. In this comment, we focused on A–D–A type molecules and device engineering, and summarized the recent developments and future challenges from the view point of chemists, including power conversion efficiencies, stability, engineering and commercialization. Meanwhile, we analyzed the challenges we are facing for the further development of OSCs for their commercialization. Some strategies and designs adopted by researchers to face these challenges are also introduced. Finally, we offer our recommendations for the next research direction in this field and aim to provide useful reference and inspiration from different aspects.