| 초록 |
A series of four donor-acceptor alternating co-polymers based on alkoxy-substituted benzothiadiazole (ROBT) acceptor and acene with varied electron donating ability (thieno[3,2-b]thiophene (TT), dithieno[3,2-b:2',3'-d] thiophene (DTT), benzo[1,2-b:4,5-b']dithiophene (BDT) and naphtha [1,2-b:5,6-b']dithiophene (NDT)) were synthesized and tested for organic solar cells. The insertion of different acenes into the polymer backbone greatly influenced the polymer band gap, energy levels, crystallinity, morphology, and photovoltaic performances. The optimized photovoltaic cells yielded efficiency of 6.25% (PTT-BOBT), 9.02% (PDTT-BOBT), 6.34% (PBDT-HDBT) and 2.29% (PNDT-HDBT). In here, the role of the donor acene in the polymer backbone was studied in-depth by analyzing and comparing molecular ordering, charge carrier mechanism and film morphologies.These findings will help us to understand the role of donor acenes on the optoelectronic and photovoltaic performances of polymers. |
