Effect of electron-withdrawing units on triphenylamine-based small molecules for solution-processed

• 作 者: Yifan Wang Huitao Bai Pei Cheng Mingyu Zhang Xiaowei Zhan
• 机 构: CAS Key Laboratory of Organic Solids,Institute of Chemistry, Chinese Academy of Sciences,University
• 出 处: Science China Chemistry
• 发表日期: 2015年02期
• 关键词: donor processed photovoltaic acceptor pyridine benzo chloroform blend PEDOT coat

Organic small molecules(TPA-BT3T,TPA-PT3T,and TPA-DFBT3T)using triphenylamine as a donor unit,terthiophene as a bridge,and benzo-2,1,3-thiadiazole(BT),[1,2,5]thiadiazolo[3,4-c]pyridine(PT)or 5,6-difluorobenzo[c][1,2,5]thiadiazole(DFBT)as an acceptor unit were designed and synthesized through Suzuki coupling reactions.These molecules exhibited good thermal stability with decomposition temperatures over 380°C and broad absorption from 300 to 700 nm.Photovoltaic devices were fabricated with these small molecules as donors and PC71BM as an acceptor.The TPA-BT3T based devices exhibited a power conversion efficiency of 2.89%,higher than those of the TPA-PT3T-and TPA-DFBT3T-based devices(1.34%and1.54%respectively).The effects of electron-withdrawing units on absorption,energy level,charge transport,morphology,and photovoltaic properties also were investigated.

(TPA-BT3T, TPA-PT3T, and TPA-DFBT3T) using triphenylamine as a donor unit, terthiophene as a bridge, and benzo-2,1,3-thiadiazole (BT) thiadiazolo [3,4-c] pyridine (PT) or 5,6-difluorobenzo [c] [1,2,5] thiadiazole (DFBT) as an acceptor unit were designed and synthesized through Suzuki coupling reactions. stability with decomposition temperatures over 380 ° C and broad absorption from 300 to 700 nm. Photovoltaic devices were fabricated with these small molecules as donors and PC71BM as an acceptor. The TPA-BT3T based devices exhibited a power conversion efficiency of 2.89%, higher than those of the TPA-PT3T-and TPA-DFBT3T-based devices (1.34% and 1.54% respectively). The effects of electron-withdrawing units on absorption, energy level, charge transport, morphology, and photovoltaic properties were also investigated.