| 초록 |
We synthesized a donor polymer consisted of chlorine and sulfur-bridged 2-ethylhexyl thiophene substituted benzodithiophene (BDT) and 1,3-bis(2-ethylhexyl)-5,7-di(thiophene-2-yl)-benzo[1,2-c:4,5-c′]dithiophene-4,8-dione. PBDB-TSCl shows more efficient exciton dissociation and charge generation than PBDB-TF includes fluorine and 2-ethylhexyl thiophene on BDT and those results are probably from reduced exciton binding energy because of large dipole moment changes between ground and excited states. Consequently, despite large phase separated morphology and a small donor-acceptor interface in the bulk heterojunction (BHJ) active layer, PBDB-TSCl shows higher power conversion efficiency (PCE) than PBDB-TF for outdoor to indoor light; PBDB-TSCl shows 13.13% of PCE under 1 sun illumination and its higher than the 12.12% of PBDB-TF. Moreover, PBDB-TSCl achieved higher PCE of 21.53% with fill factor (FF) of 76.29% than 15.57% of PBDB-TF with FF of 65.25% under a 500 lx fluorescence lamp. |
