title: Improving the Compatibility of Donor Polymers in Efficient Ternary Organic Solar Cells via Post-Additive Soaking Treatment.
abstract: In dual-donor ternary organic solar cells, the compatibility between the donor polymers plays important roles to control the conformational change and govern the photophysical behavior in the blend films. Here, we apply a post-additive soaking (PAS) approach to reconstruct the morphology in a ternary organic photovoltaic BHJ of PTB7-Th: PCDTBT: PC71BM. The PAS-treated device has a maximum power conversion efficiency (PCE) of about 8.7% in this ternary system. From the analyses of GIWAXS and GISAXS, the superior device performance is attributed to the favorable nanomorphology with optimum crystallinity of PTB7-Th and good intermixing of PCDTBT with PTB7-Th:PC71BM, leading to improved charge transport in the vertical direction. AFM and TRPL measurements clearly demonstrate PAS-treated film envisages a homogeneous distribution of smaller PC71BM aggregates to facilitate the exciton dissociation and carrier extraction at the interface. The increased PCE ascribed to not only the enhancement of absorption and nonradiative Förster resonance energy transfer (FRET) between two donors (PCDTBT and PTB7-Th) but also the formation of a bicontinuous interpenetrating network of PC71BM.
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Yang
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zheng
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Weilong
authors.initials: W
authors.lastname: Xu
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Pengqing
authors.initials: P
authors.lastname: Bi
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.|School of Chemistry, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Xiaotao
authors.initials: X
authors.lastname: Hao
keywords: FRET; PAS; morphology; photophysical process; ternary organic solar cells