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Fine Control of Side Chains in Random π‐Conjugated Terpolymers for Organic Photovoltaics
Author(s) -
Wang Jialin,
Kong Lingqiang,
Liang Ziqi
Publication year - 2016
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201600072
Subject(s) - organic solar cell , homo/lumo , side chain , solubility , thiophene , copolymer , stacking , conjugated system , polymer solar cell , materials science , fullerene , energy conversion efficiency , polymer chemistry , polymer , quenching (fluorescence) , chemical engineering , chemistry , organic chemistry , molecule , optoelectronics , fluorescence , physics , quantum mechanics , engineering
Rational molecular design of π‐conjugated donor polymers is critical for developing high‐performance organic solar cells. Random copolymerization strategy is a facile method of synergistic fine‐tuning the light absorption, HOMO/LUMO energy levels, charge mobility, and solubility of donor (D)–acceptor (A) copolymers. Terpolymers PF8TBT which composed of three components, i.e., electron‐rich 9,9‐dioctylfluorene (F8), electron‐deficient benzothiadiazole (BT), and π‐bridge thiophene (T) moieties, are designed in such a way that only F8 unit possesses soluble side‐chains. This strategy enables a facile and precise control of the influences of side chains on solubility, energy levels, molecular packing, and fullerene (PCBM) intercalation of PF8TBT. The optimal terpolymer PF8TBT21 (F8:T:BT = 0.67:1:0.33 mol%) maximally balances the solubility and the PL quenching efficiency with PCBM while exhibiting notable π–π stacking. The resulting additive‐free inverted photovoltaic cell based on the PF8TBT21:PCBM blend shows a power conversion efficiency of 3.88% with an impressive open‐circuit voltage close to 1 V.