초록 |
A new series of N-type random terpolymers was synthesized using an electron-deficient naphthalene diimide unit and two electron-rich thiophene (T) and selenophene (S) units with various T/S compositions (T/S= 100/0, 80/20, 50/50, 20/80, and 0/100). To comprehend the effects of the T/S ratios in random terpolymers, we investigated the effects of the selenophene content in polymer backbone on their optical, electrical, and structural properties. The introduction of higher S content in the polymer backbone induced the enhanced structural ordering and electron mobility. All-polymer solar cells based on the PTB7:terpolymer blends were fabricated, then there is an increasing PCE tendency from 2.5 to 3.6 % as S content increase, which is mainly attributed to enhanced short circuit current. |