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

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2017,（4）
• 页码范围: 561-569
• 页数: 9页
• 语种: 英文
• DOI: 10.1007/s11426-016-9003-9

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)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.