Despite the recent breakthroughs of polymer solar cells (PSCs) exhibiting a power conversion efficiency of over 17%, toxic and hazardous organic solvents such as chloroform and chlorobenzene are still commonly used in their fabrication, which impedes the practical application of PSCs. Thus, the development of eco-friendly processing methods suitable for industrial-scale production is now considered an imperative research focus. This Review provides a roadmap for the design of efficient photoactive materials that are compatible with non-halogenated green solvents (e.g., xylenes, toluene, and tetrahydrofuran). We summarize the recent development of green processing solvents and the processing methods to match with the efficient photoactive materials used in non-fullerene solar cells. We further review progress in the use of more eco-friendly solvents (i.e., water or alcohol) for achieving truly sustainable and ecofriendly PSC fabrication. For example, the concept of water- or alcohol-dispersed nanoparticles made of conjugated materials is introduced. Also, recent important progress and strategies to develop water/alcohol-soluble photoactive materials that completely eliminate the use of conventional toxic solvents are discussed. Finally, we provide our perspectives on the challenges facing the current green processing methods and materials, such as large-area coating techniques and long-term stability. We believe this Review will inform the development of PSCs that are truly clean and renewable energy sources.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation (NRF) of Korea (NRF-2017M3A7B8065584 and 2020R1A4A1018516). We acknowledge Prof. G. S. Collier for the helpful discussion.
© 2020 American Chemical Society.
- Eco-friendly polymer solar cells
- Eco-friendly processing
- Green solvents
- Large-area solar cells
- Long-term stability
- Non-halogenated solvents
- Organic solar cells
- Water/alcohol-based processing
ASJC Scopus subject areas
- Materials Science(all)
- Physics and Astronomy(all)