초록 |
Three alternating D-A type copolymers were synthesized through Suzuki polycondensation of the thieno[3,4-c]pyrrole-4,6-dione (TPD) acceptor unit with three different thiophene derivatives (thiophene (P1), thieno[3,2-b]thiophene (P2), to bithiophene (P3)). A carbazole unit was introduced to ensure the solubility of copolymers. Different types of thiophene spacers influence not only optical, electrochemical properties but also morphological, photovoltaic properties. Absorption was red-shifted and HOMO energy level was up-shifted in the order of P1, P2 and P3. Fabricated polymer solar cell (PSC) with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as an acceptor, showed power conversion efficiency (PCE) up to ~3%. Their structure-property relationship will be discussed in detail. |