| 초록 |
D-(π)n-A-type copolymers with different thienyl spacers between akylidenefluorene and isoindigo were synthesized via a Suzuki coupling reaction. As the spacer increased from a polymer (P1), the UV-Vis absorption maximum red- shifted, and the band gap decreased from 1.83 to 1.64 eV. The HOMO levels of the polymers were increased by increasing the number of spacers. In addition, the facile intermixing due to better accessibility with the PCBM led to an increase in the hole mobility and JSC. In contrast to P1 and P2, when the orientation of the P3 thin films was blended with PC70BM in an XRD measurement, an increased face-on structure of the crystallinity was observed. The PCE of P3 reached 4.2% when it was fabricated an inverted device at 1:2 ratio with PC70BM. |
