| 초록 |
Novel copolymers based on 5,6-difluoro-4,7-bis(6-(2-octyldodecyl)thieno[3,2-b]thiophen-2-yl)benzo[c][1,2,5]thiadiazole, PT-ttBT and PTT-ttBT, were synthesized as active materials for organic photovoltaic cells. Thiophene (T) and thieno[3,2-b]thiophene (TT) moieties were introduced as co-monomers during polymerization in order to compare optical, electrochemical, charge transport, and photovoltaic properties. The synthesized polymers possessed low bandgaps (~1.65 eV) suitable for efficient solar absorption and good solubility organic solvents such as chlorobenzene, and o-dichlorobenzene. Bulk heterojunction (BHJ) photovoltaic cells with the structure of ITO/ZnO/Polymer:PC71BM/MoO3/Ag were fabricated. The power conversion efficiency (PCE) of PTT-ttBT containing TT moiety (7.05%) was much higher than that of PT-ttBT containing T unit (6.16%), under AM 1.5G (100 mW/cm2) illumination, owing to the high crystallinity and current mobility as well as its rigid planar structure of TT. |
