Tailoring side chains of low band gap polymers for high efficiency polymer solar cells

✍ Scribed by Weiwei Li; Ruiping Qin; Yi Zhou; Mattias Andersson; Fenghong Li; Chi Zhang; Binsong Li; Zhengping Liu; Zhishan Bo; Fengling Zhang

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 795 KB
• Volume: 51
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2010.05.015

✦ Synopsis

High efficiency organic solar cells (OSCs) require conjugated polymers with a low band gap, broad absorption in visible and IR region, high carrier mobility, and relatively high molecular weight as p-type donor materials. Flexible side chains on the rigid polymer backbone are crucial for the solubility of conjugated polymers. In this work, four polymers with the main chain structure of fluorene-thiophenebenzothiadiazole-thiophene and flexible side chains located on fluorene, thiophene, and benzothiadiazole moiety, respectively, have been synthesized by SuzukieMiyauraeSchlüter polycondensation. Photovoltaic device measurements with a device configuration of ITO/polymer:PC 71 BM blends/LiF/Al show that P1 carrying octyloxy chains on benzothiadiazole rings gives the best performance, with a power conversion efficiency of 3.1%.