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

作　　者：Yifan Wang Huitao Bai Pei Cheng Mingyu Zhang Xiaowei Zhan 

机构地区：[1]CAS Key Laboratory of Organic Solids [2]Institute of Chemistry, Chinese Academy of Sciences [3]University of Chinese Academy of Sciences [4]Department of Materials Science and Engineering, College of Engineering, Peking University

出　　处：《Science China Chemistry》2015年第2期331-338,共8页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(21025418,51261130582);the National Basic Research Program of China(2011CB808401);the Chinese Academy of Sciences

摘　　要：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-e]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℃ 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 also were investigated.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.

关 键 词：organic solar cell small molecule triphenylamine electron-withdrawing unit 

分 类 号：TM914.4[电气工程—电力电子与电力传动] O625.6[理学—有机化学]