Axisymmetric and Asymmetric Naphthalene-Bisthienothiophene Based Nonfullerene Acceptors: On Constitutional Isomerization and Photovoltaic Performance
Journal article, 2020

Two pairs of constitutional isomers of fused-octacyclic nonfullerene acceptors (NFAs) based on a naphthalene-bisthienothiophene core with or without fluorination at the ending groups have been developed. Compared with the axisymmetric NFAs N66-IC and N66-2FIC with two six-member-ring bridges, their asymmetric constitutional isomers N65-IC and N65-2FIC both with one six-member-ring bridge and one five-member-ring bridge exhibit remarkable red-shifted absorption, higher crystallinity, and slightly down-shifted LUMO energy levels. Organic solar cells based on PBDB-T-2F:N65-2FIC achieved a promising power conversion efficiency of 10.19%, which is three times higher than that of its counterpart PBDB-T-2F:N66-2FIC cell (3.46%). While being blended with PBDB-T as the donor material, the asymmetric acceptor analogue N65-IC based solar cell pronounces a PCE of 9.03%, being significantly improved from that of 5.45% for the PBDB-T:N66-IC based cell, which is in consistency with the results from those cells from their both fluorinated donor and acceptor counterparts. Design rules on either both fluorinated, both nonfluorinated, or cross-combined donor/acceptors for device fabrication has been explored. In addition, PBDB-T-2F:N65-2FIC possesses very promising device stability with 85% of its initial PCE after an exposure time of 1500 h under one sun illumination, which is meaningful for their future commercial devices.

Author

Wei Hu

Hunan University of Science and Technology

Xiaoyan Du

Hunan University of Science and Technology

Wenliu Zhuang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Wenyan Su

Soochow University

Jiamin Cao

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Amir Masoud Pourrahimi

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Ning Li

Helmholtz

Xingxing Shen

Hebei University of Technology

Maojie Zhang

Soochow University

Donghong Yu

Aalborg University

Wolfgang Gruber

University of Erlangen-Nuremberg (FAU)

Tobias Unruh

University of Erlangen-Nuremberg (FAU)

Ergang Wang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Christoph J. Brabec

University of Erlangen-Nuremberg (FAU)

ACS Applied Energy Materials

25740962 (eISSN)

Vol. 3 6 5734-5744

Subject Categories

Materials Engineering

Nano Technology

Areas of Advance

Materials Science

DOI

10.1021/acsaem.0c00689

More information

Latest update

1/3/2024 9