The rapid development of low bandgap polymer acceptors has promoted the power conversion efficiency up to ~17% for all-polymer solar cells (all-PSCs). Nevertheless, the polymeric blend film, core to the photoelectric conversion of all-PSCs, has not been thoroughly understood in terms of the influence and regulatory factors of mechanical properties, which hinders the advances in flexible and wearable solar cells. Herein, we combine a range of characterization methods to thoroughly investigate the mechanical properties, miscibility, and film microstructure of the blends based on four representative polymer donors (PTzBI-Si, PTVT-T, PM6, and PTQ10) and a benchmark polymer acceptor PNDI, and further reveal the relationships of the miscibility-property. Our results stress that the fracture behaviors and elastic moduli of these blends with varied compositions can show different changing trends, which are affected by the molecular interactions and the aggregated structure of the blends. The elastic moduli of the four all-polymer blends can be nicely predicted by different models that are deduced from macromolecular mechanics. Most crucially, the correlations between elastic modulus, film morphology, and miscibility of all-polymer blends are elucidated for the first time. The derived relationships will be the key to the successful fabrication of mechanically robust and stretchable all-PSCs with high efficiency.

Unraveling the correlations between mechanical properties, miscibility and film microstructure in all-polymer photovoltaic cells

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.