Ji J, Zhu L, Xiong X, Liu F, Liang Z. Developing Y-Branched Polymer Acceptor with 3D Architecture to Reconcile Between Crystallinity and Miscibility Yielding >15% Efficient All-Polymer Solar Cells.
ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022;
9:e2200864. [PMID:
35595683 PMCID:
PMC9313542 DOI:
10.1002/advs.202200864]
[Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 04/13/2022] [Indexed: 06/15/2023]
Abstract
In all-polymer solar cells (all-PSCs), there remains such a dilemma that obtains good miscibility and crystallinity simultaneously. Herein a new family of Y-shape polymer acceptor, namely PYTT is developed, which is copolymerized from Y6 and benzotrithiophene units in three-way directions. Benefiting from its high-density end-chains and extended π-conjugation thanks to highly-branched 3D architecture, PYTT displays better organic solubility despite much higher molecular weights, larger crystallinity, and tighter π-stacking than the linear counterpart-PYT comprising Y6 and thiophene moieties, while showing identical optical absorption yet threefold higher photoluminescence intensity. In PYTT blend film with PM6 polymer donor, the interpenetrating nano-fibrillar structures are formed with well-intermixed polymeric domain sizes close to the exciton diffusion length, which is greatly conducive to exciton dissociation and charge transport in device. Consequently, PYTT-based all-PSCs exhibit all increased photovoltaic parameters, yielding a decent power conversion efficiency of 15.60%, which is ≈20% enhancement over PYT-based device, along with low nonradiative loss of 0.221 meV.
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