| 초록 |
PBDTT-DbiT-DFQx (in) and PBDTT-DbiT-DFQx (out) had completely dissolve in common solvent. Polymer (in) and polymer (out) indicated λmax at 538~547 nm in CB solution and at 555~564 nm in thin film state, Egopt at 1.86~1.90 eV. Polymer (out) showed shoulder peak in solution state and the peak intensity enhanced in film state. The shoulder peak in long wavelength happened because of π-π* intermolecular transitions and it was caused by aggregation of the side chain. These polymers showed a highest occupied molecular orbital (HOMO) energy level of -5.21, -5.29 eV and lowest unoccupied molecular orbital (LUMO) energy level of -3.35, -3.39 eV, respectively. Polymer (in) showed better Voc and FF compared to polymer (out) because of good π-π stacking and effective side chain orientation. Under optimized conditions, the efficiency of Polymer (in) was achieved 4.07% of power conversion efficiencies, Voc of 0.67 V, Jsc of 9.83 mA/cm2, FF of 0.62%. |
