| 초록 |
A series of novel photoactive conjugated low band-gap copolymers (CPFB, CPFCz, CPSB and CPSCz) and terpolyemr (TPFBCz-n and PSCz-n, n=1 to 6) based on N-alkyl carbazole, 9,9’-dialkyl fluorene, bis(thienyl) bezothiadiazole were synthesized using a Suzuky coupling reaction. The studies of the hetero junction photo voltaic cells based on the terpolymers as donor material and PCBM(71) as an acceptor material showed PCEs from 2.37 to 2.62 %. Among the mixtures, the composition of 25 wt % of terpolymer bearing 2.5 mol. % of the carbazole unit, TPFBCz-1, and 75 wt % of PCBM(71) showed a high power conversion efficiency of 2.62% with a large open-circuit voltage of 0.82 V, short circuit current of 8.01 mA and fill factor of 0.37 under AM 1.5 spectral illumination. Our findings suggest that terpolyemr bearing low concentration of carbazole lead to a high power conversion efficiency with improved short-circuit current due to high charge mobility of carbazole unit. |
