A-D-A small molecule donors based on pyrene and diketopyrrolopyrrole for organic solar cells  

作　　者：Jing-Qi Xu Wenqing Liu Shi-Yong Liu Jun Ling Jiangquan Mai Xinhui Lu Chang-Zhi Li Alex K.-Y. Jen Hongzheng Chen 

机构地区：[1]Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, State Key Laboratory of Silicon Materials Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China [2]Department of Physics, Chinese University of Hong Kong, New Territories, China [3]Department of Materials Science & Engineering, University of Washington, Seattle, Washington 98195, USA

出　　处：《Science China Chemistry》2017年第4期561-569,共9页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(51473142,21674093,21374075);the Major State Basic Research Development Program(2014CB643503);International Science and Technology Cooperation Program of China(2016YFE0102900)

摘　　要：Three new electron donating small molecules （SMs）, Pyr（EH-DPP）2, Pyr（HD-DPP）2 and PyrA（EH-DPP）2, are designed and synthesized through coupling electron rich pyrene core with electron deficient diketopyrrolopyrrole （DPP） terminals, of which the derived organic solar cells （OSCs） exhibit interesting structure-performance correlation. It shows that the tune of their solubilizing side chains and n-bridge for the acceptor-donor-acceptor （A-D-A） SMs can significantly alter the resultant short-circuit current density and power conversion efficiency （PCE） in OSCs. The Pyr（EH-DPP）2 with short side chains displays broader absorption and higher hole mobility than the Pyr（HD-DPP）2 with long side chains. Although showing planar structure, the acetylene bridge-incorporated PyrA（EH-DPP）2 adapts an undesired edge-on packing and strong aggregation in film, leading to non-ideal morphology and poor miscibility with fullerene acceptors. As a result, the PCE of the solar cell based on Pyr（EH-DPP）2 is several times higher than those based on Pyr（HD-DPP）： and PyrA（EH-DPP）2, indicating the A-D-A combination of polyaromatics with DPP would be the promising skeleton for developing photovoltaic semiconductors.Three new electron donating small molecules(SMs),Pyr(EH-DPP)_2,Pyr(HD-DPP)_2 and PyrA(EH-DPP)_2,are designed and synthesized through coupling electron rich pyrene core with electron deficient diketopyrrolopyrrole(DPP) terminals,of which the derived organic solar cells(OSCs) exhibit interesting structure-performance correlation.It shows that the tune of their solubilizing side chains and π-bridge for the acceptor-donor-acceptor(A-D-A) SMs can significantly alter the resultant short-circuit current density and power conversion efficiency(PCE) in OSCs.The Pyr(EH-DPP)_2 with short side chains displays broader absorption and higher hole mobility than the Pyr(HD-DPP)_2 with long side chains.Although showing planar structure,the acetylene bridge-incorporated PyrA(EH-DPP)_2 adapts an undesired edge-on packing and strong aggregation in film,leading to non-ideal morphology and poor miscibility with fullerene acceptors.As a result,the PCE of the solar cell based on Pyr(EH-DPP)_2 is several times higher than those based on Pyr(HD-DPP)_2 and PyrA(EH-DPP)_2,indicating the A-D-A combination of polyaromatics with DPP would be the promising skeleton for developing photovoltaic semiconductors.

关 键 词：solution-processed small molecules DIKETOPYRROLOPYRROLE PYRENE organic solar cells 

分 类 号：O626[理学—有机化学] TM914.4[理学—化学]