5-Alkyloxy-6-fluorobenzo[c][1,2,5]thiadiazole- and Silafluorene-Based D鈥揂 Alternating Conjugated Polymers: Synthesis and Application in Polymer Photovoltaic Cells

详细信息    查看全文

• 作者：Guangwu Li ; Chong Kang ; Xue Gong ; Jicheng Zhang ; Cuihong Li ; Youchun Chen ; Huanli Dong ; Wenping Hu ; Fenghong Li ; Zhishan Bo
• 刊名：Macromolecules
• 出版年：2014
• 出版时间：July 22, 2014
• 年：2014
• 卷：47
• 期：14
• 页码：4645-4652
• 全文大小：567K
• ISSN：1520-5835

文摘

Three donor鈥揳cceptor (D鈥揂) alternating conjugated polymers with silafluorene as the donor unit, 5-alkyloxy-6-fluorobenzothiadiazole as the acceptor unit, and thiophene as the spacer has been synthesized and used as donor materials for polymer solar cells (PSCs). The introduction of a fluorine atom on the benzothiadiazole unit can lower the HOMO and LUMO energy level of the resulted polymers to afford higher open circuit voltage (V_oc); whereas the introduction of a flexible alkyloxy chain on benzothiadiazole unit can increase the solubility of the resulted polymers without interfering the close packing of polymer chains in the solid state. High molecular weight polymers P-1a, P-1b, and P-1c, which are fully soluble in 1,2-dichorobenzene (DCB) at elevated temperature, have been prepared by Suzuki polycondensation. Among these polymers, P-1c exhibited the highest hole mobility up to 1.36 脳 10^鈥? cm² V^鈥? s^鈥?. PSCs based P-1b:PC₇₁BM demonstrated the highest V_oc up to 0.98 V. P-1a:PC₇₁BM based PSCs gave the highest power conversion efficiency (PCE) of 6.41%, which is the highest value among solar cells with benzothiadiazole- and silafluorene-containing polymers as the donor material.