title: Non-fullerene organic solar cells based on diketopyrrolopyrrole polymers as electron donors and ITIC as an electron acceptor.
abstract: In this work, we provide systematic studies on the non-fullerene solar cells based on diketopyrrolopyrrole (DPP) polymers as electron donors and a well-known electron acceptor ITIC. ITIC has been widely reported in non-fullerene solar cells with high power conversion efficiencies (PCEs) above 10%, when it is combined with a wide band gap conjugated polymer, while its application in small band gap DPP polymers has never been reported. Herein, we select four DPP polymers containing different thienyl linkers, resulting in distinct absorption spectra, energy levels and crystalline properties. Non-fullerene solar cells based on DPP polymers as donors and ITIC as an acceptor show PCEs of 1.9-4.1% and energy loss of 0.55-0.82 eV. The PCEs are much lower than those of cells based on fullerene derivatives due to the poor miscibility between the DPP polymers and ITIC, as confirmed by the morphology and charge transport investigation. The results indicate that it is important to tune the miscibility between the donor and acceptor in order to realize optimized micro-phase separation, which can further enhance the performance of DPP polymer based non-fullerene solar cells.
authors.affiliation: Department of Chemistry, School of Science, Beijing Jiaotong University, Beijing 100044, P. R. China. yhxu@bjtu.edu.cn and Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China. liweiwei@iccas.ac.cn.
authors.forename: Xudong
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Chemistry, School of Science, Beijing Jiaotong University, Beijing 100044, P. R. China. yhxu@bjtu.edu.cn.
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, P. R. China. msewma@xjtu.edu.cn.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, P. R. China. msewma@xjtu.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Chemistry, School of Science, Beijing Jiaotong University, Beijing 100044, P. R. China. yhxu@bjtu.edu.cn and Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China. liweiwei@iccas.ac.cn.
authors.forename: Guitao
authors.initials: G
authors.lastname: Feng
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China. liweiwei@iccas.ac.cn.
authors.forename: Cheng
authors.identifier: http://orcid.org/0000-0001-9377-9049
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, P. R. China. msewma@xjtu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Ma
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China. liweiwei@iccas.ac.cn.
authors.forename: Weiwei
authors.identifier: http://orcid.org/0000-0002-7329-4236
authors.initials: W
authors.lastname: Li