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.

co-crystals

non-fullerene acceptors

suppressed crystallization

ternary solar cells

glass transition temperatures

Author

Sandra Hultmark

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Christian Müller Group

Sri Harish Kumar Paleti

King Abdullah University of Science and Technology (KAUST)

Albert Harillo

Institute of Material Science of Barcelona (ICMAB)

Sara Marina

Institute for Polymer Materials, San Sebastian

Basque Foundation for Science (Ikerbasque)

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

Institute of Material Science of Barcelona (ICMAB)

Ellen Moons

Karlstad University

Derya Baran

King Abdullah University of Science and Technology (KAUST)

Christian Müller

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Christian Müller Group

Advanced Functional Materials

1616-301X (ISSN)

Vol. 30 48 2005462

Subject Categories

Inorganic Chemistry

Ceramics

Materials Chemistry

DOI

10.1002/adfm.202005462

More information

Latest update

1/4/2021 3