Suppressing Co-Crystallization of Halogenated Non-Fullerene Acceptors for Thermally Stable Ternary Solar Cells
Journal article, 2020
While photovoltaic blends based on non-fullerene acceptors are touted for their thermal stability, this type of acceptor tends to crystallize, which can result in a gradual decrease in photovoltaic performance and affects the reproducibility of the devices. Two halogenated indacenodithienothiophene-based acceptors that readily co-crystallize upon mixing are studied, which indicates that the use of an acceptor mixture alone does not guarantee the formation of a disordered mixture. The addition of the donor polymer to the acceptor mixture readily suppresses the crystallization, which results in a fine-grained ternary blend with nanometer-sized domains that do not coarsen due to a high Tg ≈ 200 °C. As a result, annealing at temperatures of up to 170 °C does not markedly affect the photovoltaic performance of ternary devices, in contrast to binary devices that suffer from acceptor crystallization in the active layer. The results indicate that the ternary approach enables the use of high-temperature processing protocols, which are needed for upscaling and high-throughput fabrication of organic solar cells. Further, ternary devices display a stable photovoltaic performance at 130 °C for at least 205 h, which indicates that the use of acceptor mixtures allows to fabricate devices with excellent thermal stability.
non-fullerene acceptors
ternary solar cells
co-crystals
suppressed crystallization
glass transition temperatures
Author
Sandra Hultmark
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Sri Harish Kumar Paleti
King Abdullah University of Science and Technology (KAUST)
Albert Harillo
Spanish National Research Council (CSIC)
Sara Marina
Basque Foundation for Science (Ikerbasque)
Institute for Polymer Materials, San Sebastian
Ferry Nugroho
Chalmers, Physics, Chemical Physics
Yanfeng Liu
Linköping University
L. K. E. Ericsson
Karlstad University
Ruipeng Li
Brookhaven National Laboratory
Jaime Martín
Institute for Polymer Materials, San Sebastian
Basque Foundation for Science (Ikerbasque)
J. Bergqvist
Linköping University
Christoph Langhammer
Chalmers, Physics, Chemical Physics
Fengling Zhang
Linköping University
Liyang Yu
Sichuan University
M. Campoy-Quiles
Spanish National Research Council (CSIC)
Ellen Moons
Karlstad University
Derya Baran
King Abdullah University of Science and Technology (KAUST)
Christian Müller
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Advanced Functional Materials
1616-301X (ISSN) 16163028 (eISSN)
Vol. 30 48 2005462Subject Categories (SSIF 2011)
Ceramics
Materials Chemistry
Other Physics Topics
DOI
10.1002/adfm.202005462