초록 |
Organic solar cells (OSCs) have attracted much attention due to light weight, flexibility, and low fabrication cost. Recently, the series of poly(thieno[3,4-b]thiophene)benzothiophene (PTB) copolymers such as PTB7 and PBDTTT-C-T have been developed for high-efficiency PSCs. Although the PTB copolymers possess various merits such as high hole mobility and low bandgap, the PTB copolymers absically possess random structural regioregularity since the TT segment has an asymmetric molecular structure. In this study, we successfully synthesized a regioregular PBDTTT-C-T comprised of TT-BDT-TT-BDT repeating units. The device performance of BHJ OSCs with regioregular PBDTTT-C-T and PC71BM exhibited a power conversion efficiency as high as 7.79%, which was 19% higher than the random PBDTTT-C-T based PSCs. |