| 초록 |
We synthesized two new low band gap co-polymers, PDFDB-HD and PDFDB-BO. The polymers are composed of electron-rich dithieno[3,2-b, 2´,3´-d]silole (DTS), benzo[1,2-b, 4,5-b´]dithiophene (BDT) and electron-deficient 2,1,3-benzothiadiazole (BTD) units via Stille coupling reaction. The maximum UV-visible absorptions of the polymers were at around 650 nm in diluted solution and approximately 740 nm in thin film with optical band gap about 1.6 eV. Using these polymers, we fabricated devices with a structure of ITO/PEDOT:PSS/polymers:PC71BM/TiO2/Al and measured photovoltaic performance under 100 mW/cm2, AM 1.5G illumination. Photovoltaic devices based on the PDFDB-HD and PC71BM blend showed an open-circuit voltage (Voc) of 0.8 V, a short-circuit current (Jsc) of 11.3 mA/cm2, a fill factor (FF) of 0.6 and a power conversion efficiency (PCE) of 5.5%. In the case of the PDFDB-BO and PC71BM blend exhibited a Voc of 0.8 V, a Jsc of 11.8 mA/cm2, a FF of 0.6, and a PCE of 6.0%. |
