A novel naphthyl side-chained benzodithiophene polymer for efficient photovoltaic cells with a high fill factor of 75%

作者：Ding, Dakang; Wang, Jiuxing; Du, Zurong; Li, Feng; Chen, Weiye; Liu, Fushuai; Li, Haiyan; Sun, Mingliang^*; Yang, Renqiang^*

来源：Journal of Materials Chemistry A, 2017, 5(21): 10430-10436.

DOI：10.1039/c7ta01994g

• OPEN-CIRCUIT VOLTAGE
• ORGANIC SOLAR-CELLS
• BAND-GAP
• CONJUGATED POLYMERS
• SEMICONDUCTING POLYMERS
• PI-CONJUGATION
• AGGREGATION
• PERFORMANCE
• COPOLYMERS
• SUBSTITUENTS

To study which strategy (extending side chain pi-conjugation with single-bonded or fused aromatic rings) is more effective in improving the photovoltaic properties of benzodithiophene (BDT)-based polymers, naphthyl (NP) and biphenyl (BP) units were introduced to the BDT core as conjugated side chains. Two polymers PBDTNP-DTBO and PBDTBP-DTBO based on NP or BP-substituted BDT and 5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]oxadiazole (DTBO) were designed. These two polymers only exhibited small differences in the chemical structure, but great differences in photovoltaic performance. PBDTNP-DTBO showed a high power conversion efficiency (PCE) of 8.79%, with an open-circuit voltage (V-oc) of 0.82 V, a short-circuit current density (J(sc)) of 14.34 mA cm(-2), and a fill factor (FF) of 74.73%, while PBDTBP-DTBO only showed a maximum PCE of 6.69%, with a V-oc of 0.75 V, a J(sc) of 13.55 mA cm(-2), and a FF of 65.86%. Hence, extending the side chain pi-conjugation system of a BDT-based polymer with naphthyl is a more effective method to enhance the photovoltaic properties.

• 出版日期2017-6-7
• 单位青岛科技大学; 青岛大学; 中国科学院青岛生物能源与过程研究所; 中国海洋大学