The role of connectivity in significant bandgap narrowing for fused-pyrene based non-fullerene acceptors toward high-efficiency organic solar cells
Artikel i vetenskaplig tidskrift, 2020

Great attention has been paid to developing low bandgap non-fullerene acceptors (NFAs) for matching wide bandgap donor polymers to increase the photocurrent and therefore the power conversion efficiencies (PCEs) of NFA organic solar cells, while pyrene-core based acceptor-donor-acceptor (A-D-A) NFAs have been mainly reported via the 2,9-position connection due to their bisthieno[3′,2′-b']thienyl[a,h]pyrene fused via a five-membered ring bridge at the ortho-position of pyrene as the representative one named FPIC5, which has prohibited further narrowing their energy gap. Herein, an acceptor FPIC6 was exploited by creating the 1,8-position connection through fusing as bisthieno[3′,2′-b′]thienyl[f-g,m-n]pyrene linked at the bay-position via a six-membered bridge, with enhanced push-pull characteristics within such A-D-A structure. As a structural isomer of FPIC5, FPIC6 exhibited a much lower bandgap of 1.42 eV (1.63 eV for FPIC5). Therefore, the photocurrent and PCE of PTB7-Th:FPIC6 cells were improved to 21.50 mA cm-2 and 11.55%, respectively, due to the balanced mobilities, better photoluminescence quenching efficiency and optimized morphology, which are both ∼40% better than those of PTB7-Th:FPIC5 cells. Our results clearly proved that a pyrene fused core with 1,8-position connection with electron-withdrawing end groups instead of 2,9-position connection is an efficient molecular design strategy to narrow the optical bandgap and improve the photovoltaic performance of NFA based OSCs.

Författare

Shungang Liu

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Hunan University of Science and Technology

Wenyan Su

Soochow University

Xianshao Zou

Lunds universitet

Xiaoyan Du

Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)

Jiamin Cao

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Hunan University of Science and Technology

Nong Wang

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Xingxing Shen

Hebei Normal University of Science and Technology

Xinjian Geng

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Zilong Tang

Hunan University of Science and Technology

A. Yartsev

Lunds universitet

Maojie Zhang

Soochow University

Wolfgang Gruber

Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)

Tobias Unruh

Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)

Ning Li

Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)

Donghong Yu

Aalborg Universitet

Sino-Danish Center for Education and Research (SDC)

Christoph J. Brabec

Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)

Ergang Wang

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Ergang Wang Group

Zhengzhou University

Journal of Materials Chemistry A

20507488 (ISSN) 20507496 (eISSN)

Vol. 8 12 5995-6003

Ämneskategorier

Polymerkemi

Materialkemi

Organisk kemi

DOI

10.1039/d0ta00520g

Mer information

Senast uppdaterat

2020-05-08