| 초록 |
The absorption spectra in solution had maximum peaks at 800 and 718 nm and in solid film had maximum peaks at 800 and 655 nm in PbiTz-DFQx, PbiTz-DTDFQx, respectively. As shown these results, PbiTz-DTDFQx containing more thiophene unit in polymer backbone was blue-shifted. The optical bandgap (Egopt) inferred from the onset (867~829 nm) of the polymer absorption edges in the films is 1.47~1.54 eV. In two polymers, PbiTz-DFQx showed somewhat high value of Jsc 7.40 mA/cm2. It was caused by broad UV-vis absorption region, which effect the light absorption. On the other hand, PbiTz-DTDFQx had a poor solubility in common solvent like chloroform, toluene and chlorobenzene. Therefore, device based on PbiTz-DTDFQx could not make to measure photovoltaic properties. Since the HOMO level of donor material is related with Voc, PbiTz-DFQx had somewhat low Voc value 0.50 V. As a result, PbiTz-DFQx showed 0.87% of power conversion efficiency(PCE). |
