Crystallinity and Orientation Manipulation of Anthracene Diimide Polymers for All-Polymer Solar Cells

Electron-carrying polymers are highly desired for various optoelectronic applications but are still scarce. Herein, two anthracene diimide (ADI) polymers with thiophene and bithiophene as comonomer, respectively, are reported as electron acceptor materials in all-polymer solar cells (all-PSCs) for the first time. Effects of crystallinity and orientation of two polymer films as well as their blends with different donor polymers on photovoltaic properties are elaborately investigated by grazing-incidence X-ray diffraction and photo-induced force microscopy. It is found that molecular crystallinity and orientation determine the blend film morphology, and the similar high crystallinity and the same face-on orientation of donor and acceptor polymers are favorable for obtaining excellent photovoltaic performances. With this principle, a suitable donor polymer is singled out to match with the ADI acceptor polymer, offering an impressive efficiency of approximate to 7% for all-PSCs. This work demonstrates that ADI polymers are promising as acceptor materials and provides guidelines for screening donor and acceptor polymer combinations for all-PSCs.

Automated summary

This study reports the application of two new anthracene diimide (ADI) polymers as electron acceptor materials in all-polymer solar cells for the first time, and investigates the effects of crystallinity and orientation of blend films on photovoltaic properties. The research finds that high crystallinity and the same orientation of donor and acceptor polymers are crucial for achieving excellent photovoltaic performance.