| 초록 |
The novel alternating copolymers (PBDT-DT-DFQx and PBDT-DT-FQx) containing doubly or singly fluorinated quinoxaline (Qx) unit were synthesized by a Stille coupling reaction to investigate the effect of fluorine atom. Thieophene bridge was introduced in the polymers to play a role as molecular spacer on conjugated backbone. These polymers displayed an optical bandgap of 1.97–2.00 eV, with highest occupied molecular orbital (HOMO) energy around -5.50 eV. The polymers showed strong absorption in the range of 400 - 650 nm in film state. Bulkheterojunction (BHJ) solar cells were further fabricated by blending the as-prepared polymer with (6,6)-phenyl-C60-butyric acid methyl ester (PC60BM) or (6,6)-phenyl-C70-butyric acid methyl ester (PC70BM) at different weight ratios. As a result, PBDT-DT-DFQx was achieved 5.58 % of power conversion efficiency (PCE) with a Voc of 0.79 V, Jsc of 10.44 mA/cm2, FF of 0.68 %. |
