High-efficiency non-halogenated solvent processable polymer/PCBM solar cells via fluorination-enabled optimized nanoscale morphology

摘要: PNTz4T-based polymers have been extensively employed in high-efficiency fullerene-based polymer solar cells (PSCs) with a power conversion efficiency (PCE) of approximately 10.0% due to the high crystallinity these polymers. The introduction two fluorine atoms into PNTz4T synthesize PNTz4T-2F has boosted PCE 10.6%, but four PNTz4T-4F negatively affects (PCE = 6.5%), implying that number is not yet optimized. We developed new synthetic route for novel monofluoro-bithiophene monomer and successfully synthesized PNTz4T-1F polymer. PSCs based on our processed using halogen-free solvent system demonstrated an outstanding 11.77% (11.67% certified), representing highest reported thus far literature. Due optimum molecular ordering/packing, improved interaction PC71BM interconnectivity between photoactive material domains, PNTz4T-1F-based exhibit lower charge carrier recombination enhanced mobility levels, leading substantially photocurrent density (20.37 mA cm−2). These results create means tune structural properties polymers, ultimately realization this class practical applications.