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论文类型：期刊论文

发表时间：2020-05-01

发表刊物：DYES AND PIGMENTS

收录刊物：EI、SCIE

卷号：176

ISSN号：0143-7208

关键字：Zn-porphyrin; Diketopyrrolopyrrole; Asymmetrical backbone; Organic solar cells; Small-molecule donors

摘要：Three novel organic small molecules based on asymmetric porphyrin-diketopyrrolopyrrole (DPP) backbone, namely ZnPTDPP, ZnPTDPPCN and ZnPTDPPO, have been designed and synthesized for solution-processed organic solar cells (OSCs). The terminal units of 4-cyanophenyl and 4-methoxyphenyl were introduced into ZnPTDPPCN and ZnPTDPPO respectively, and the structural modification effects on photoelectric and photovoltaic performance were fully investigated. Depending on the characteristics of porphyrin and DPP, all three molecules possess narrow bandgaps of lower than 1.50 eV, showing excellent absorption properties. Structural modification of terminal groups can effectively regulate energy levels of ZnPTDPPCN and ZnPTDPPO. As expected, extended molecular structure from D-A type to D-A-A(1) or D-A-D-1 type, was conducive to enlarging the pi-conjugation and affecting the push-pull effect of intramolecular electrons, thus affecting the photoelectric character of materials. Solution-processed OSCs employing these molecules as the donor materials and PC61BM as the acceptor material were fabricated. It was worth mentioning that devices based on materials ZnPTDPPCN and ZnPTDPPO achieved moderate power conversion efficiencies (PCEs) of 4.26% and 4.24%, respectively, while ZnPTDPP showed an inferior PCE of 1.46%. To our knowledge, the work based on asymmetric porphyrin-DPP backbone for solution-processed OSCs, is first reported. The work will provide valuable hints for rational design of asymmetric porphyrin-based donor materials.