Decoding the Structure of Benzodithiophene Polymers for High-Efficiency Organic Solar Cells
Artikel i vetenskaplig tidskrift, 2025

The performance of organic electronic devices, such as solar cells, depends on understanding and controlling the solid-state microstructure of semiconducting polymers. In this study, a detailed understanding of the aggregate states, solid-state microstructure, and thermotropic behavior of the best-performing family of polymers for solar cells, i.e., benzodithiophene-based semiconducting polymers, is provided. Using D18, PBnDT-FTAZ, and PBDB-T-Cl as model systems, this study reveals a unique solid mesophase, distinct from previously observed polymer mesophases, comprising stacked solid-like and liquid-like layers. This mesophase resembles sanidic structures while also sharing features with columnar mesophases like condis crystals and paracrystals. At a larger length scale, it organizes into nanoscale fibril-like domains, with polymer backbones aligned along the fibril axis, coexisting with amorphous-like glassy regions, reported here for the first time. Notably, high-performance polymers such as D18, D18-Cl, and PM6 contain minimal glassy regions. The thermotropic behavior of this biphasic nanomorphology is also examined, providing insights into how thermal annealing influences polymer structure. Understanding these solid-aggregate states, the microstructure, and the thermal behavior enables a more precise framework for defining structure–function relationships in semiconducting polymers. This will have a significant impact on the entire field of organic electronics, from organic photovoltaics to bioelectronics to wearable electronics.

mesophases

organic solar cells

crystallization

semiconducting polymers

polymer structure

Författare

Matteo Sanviti

Universidade da Coruña

Sara Marina

Universidad del Pais Vasco / Euskal Herriko Unibertsitatea

Xabier Rodriguez-Martínez

Universidade da Coruña

Jesika Asatryan

Universidade da Coruña

Valerio Di Lisio

Donostia International Physics Center

Sandra Hultmark

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Junkal Gutierrez

Universidad del Pais Vasco / Euskal Herriko Unibertsitatea

Eduardo Solano

El Sincrotrón ALBA

Jeromy J. Rech

College of Arts & Sciences

Eugenio L. Solla

Universidade da Coruña

Wei You

College of Arts & Sciences

Agnieszka Tercjak

Universidad del Pais Vasco / Euskal Herriko Unibertsitatea

M. Eugenio Vázquez

Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS)

Daniele Cangialosi

Donostia International Physics Center

Consejo Superior de Investigaciones Científicas (CSIC)

Christian Müller

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Harald Ade

North Carolina State University

Jaime Martín

Universidade da Coruña

Advanced Functional Materials

1616-301X (ISSN) 16163028 (eISSN)

Vol. In Press

Acceptor Blandningar med Hög Entropi för Stabila Organiska Solceller

Vetenskapsrådet (VR) (2022-02977), 2023-01-01 -- 2026-12-31.

Ämneskategorier (SSIF 2025)

Den kondenserade materiens fysik

Fysikalisk kemi

DOI

10.1002/adfm.202503634

Mer information

Senast uppdaterat

2025-06-03