Low-cost and efficient organic solar cells based on polythiophene- and poly(thiophene vinylene)-related donors

At present, most of state-of-the-art power conversion efficiencies (PCEs) of organic solar cells (OSCs) are achieved from the photoactive materials involving donoracceptor (D-A) copolymer donors. It is well known that the complicated molecular structure of D-A copolymers means the tedious synthesis, which brings about severe cost issue and poor scalability for the industrial production. Therefore, to develop application-oriented OSCs, considerable attention should be paid on simplifying the chemical structures of polymer donors. Polythiophene (PT) and poly(thiophene vinylene) (PTV) derivatives should be among the simplest polymer donors, and OSCs based on them have made some breakthroughs in past 2 years. Here, we briefly introduce the recent advances of OSCs based on low-cost polymers including poly(3-hexylthiophene) (P3HT), PT derivatives, and PTV derivatives, respectively, and emphasize the importance of modulating energy levels, preaggregation effect, and D/A miscibility for the past progress as well as the future development. At last, we also propose some challenges demanding prompt solution for realizing practical application of OSCs, aiming at providing guidance and stimulating new ideas for further research.