Solid-liquid convertible fluorinated terthiophene as additives in mediating morphology and performance of organic solar cells

The fluorinated terthiophene ([2F]3T) additive can be changed from solid to liquid under thermal annealing, and thus provides meaningful roles as nucleation centers and plasticizers in reaching favorable photoactive layers with increased crystallinity and P-i-N like heterojunction. Consequently, the resulted organic solar cells showed significantly improved efficiency of 17.6%, higher than the efficiency of 16.3% reached in control devices.