Chlorinated Thiazole-Based Low-Cost Polymer Donors for High Efficiency Binary and Ternary Organic Solar Cells

In this work, novel D–A alternating polymers ( PJ-1, PJ-2, and PJ-3) with chlorinated benzodithiophene and chlorinated thiazole units were synthesized via gradual chlorination. These polymers could be obtained readily through a few concise synthesis steps. Among them, PJ-1 displayed desirable properties including energy levels, crystallinity, and charge transport capabilities. The binary and ternary organic solar cells (OSCs) fabricated based on PJ-1 displayed significant power conversion efficiency (PCE) of 15.02% and 19.12%, respectively, placing them among the highest reported for ternary OSCs. Notably, the PJ1-based devices also showcased one of the highest figure-of-merit values, indicating their promising potential for future applications. This study offers valuable insights and supports the development of cost-effective and high-performance polymer donors for the generation of OSCs.