Synthesis of two-dimensional π-conjugated polymers pendent with benzothiadiazole and naphtho[1,2-c:5

• 作 者: Wei Li Qingduan Li Shengjian Liu Chunhui Duan Lei Ying Fei Huang Yong Cao
• 机 构: Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Mater
• 出 处: Science China Chemistry
• 发表日期: 2015年02期
• 关键词: conjugated moiety butyric acceptor donor resultant carbazole octyl copolymer bac

Four new 2D donor–acceptor conjugated polymers were designed and synthesized.These new polymers comprised fluorenealt-triphenylamine or carbazole-alt-triphenylamine as the backbones,and pendants with 2,1,3-benzothiadiazole(BT)or naphtho[1,2-c:5,6-c]bis[1,2,5]thiadiazole(NT)in a triphenylamine unit as the side groups.By changing the acceptor BT for a stronger electron-withdrawing unit of NT moiety in the side chain,the energy levels,absorption spectra,band gaps,and charge-transport abilities of the resultant polymers could be effectively tuned.Bulk heterojunction solar cells with these polymers as the electron donors and(6,6)-phenyl-C71-butyric acid methyl ester as the electron acceptor exhibited high open-circuit voltage(more than 0.8 e V).The power conversion efficiency can be improved from 1.37%to 3.52%by replacing the BT with an NT moiety,which indicates that introducing NT as the side-chain building block can be an effective strategy to construct efficient 2D conjugated polymers for PSCs.

Four new 2D donor-acceptor conjugated polymers were designed and synthesized. The new polymers comprised fluorene-triphenylamine or carbazole-alt-triphenylamine as the backbones, and pendants with 2,1,3-benzothiadiazole (BT) or naphtho [1,2- c: 5,6-c] bis [1,2,5] thiadiazole (NT) in a triphenylamine unit as the side groups. By changing the acceptor BT for a strengthened electron-withdrawing unit of NT moiety in the side chain, the energy levels, absorption spectra, band gaps, and charge-transport abilities of the resulting polymers could be significantly tuned.Bulk heterojunction solar cells with these polymers as the electron donors and (6,6) -phenyl-C71-butyric acid methyl ester as the electron acceptor exhibited a high open-circuit voltage (more than 0.8 eV). The power conversion efficiency can be improved from 1.37% to 3.52% by replacing the BT with an NT moiety, which indicates that introducing NT as the side-chain building block can be an effective strategy to construct efficient 2D conjugated polymers for PSCs.