Premium
Feasible D1–A–D2–A Random Copolymers for Simultaneous High‐Performance Fullerene and Nonfullerene Solar Cells
Author(s) -
Jeong Mingyu,
Chen Shanshan,
Lee Sang Myeon,
Wang Zhiwei,
Yang Yankang,
Zhang ZhiGuo,
Zhang Chunfeng,
Xiao Min,
Li Yongfang,
Yang Changduk
Publication year - 2018
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201702166
Subject(s) - materials science , polymer solar cell , fullerene , thiophene , copolymer , organic solar cell , energy conversion efficiency , absorption (acoustics) , acceptor , electron acceptor , population , chemical engineering , polymer chemistry , polymer , organic chemistry , chemistry , optoelectronics , composite material , physics , engineering , condensed matter physics , demography , sociology
A series of PBDB‐TT n random donor copolymers is synthesized, consisting of an electron‐deficient benzo[1,2‐ c :4,5‐ c ′]dithiophene‐4,8‐dione (BDD) unit and different ratios of two electron‐rich benzo[1,2‐b:4,5‐ b ′]dithiophene (BDT) and thieno[3,2‐ b ]thiophene (TT) units, with intention to modulate the intrachain and/or interchain interactions and ultimately bulk‐heterojunction morphology evolution. A comparative study using 4 × 2 polymer solar cell (PSC) performance maps and each of the [6,6]‐phenyl‐C 71 ‐butyric acid methyl ester (PC 71 BM) and the fused‐aromatic‐ring‐based molecule ( m ‐ITIC) acceptors are carried out. Given the similarities in their absorption ranges and energy levels, the PBDB‐TT n copolymers clearly reveal a change in the absorption coefficients upon optimization of the BDT to TT ratio in the backbone. Among the given acceptor combination sets, superior performances are observed in the case of PBDB‐TT5 blended with PC 71 BM (8.34 ± 0.10%) or m ‐ITIC (11.10 ± 0.08%), and the dominant factors causing power conversion efficiency differences in them are found to be distinctly different. For example, the performances of PC 71 BM‐based PSCs are governed by size and population of face‐on crystallites, while intermixed morphology without the formation of large phase‐separated aggregates is the key factor for achieving high‐performance m ‐ITIC‐based PSCs. This study presents a new sketch of structure–morphology–performance relationships for fullerene‐ versus nonfullerene‐based PSCs.