Tailoring polymer acceptors by electron linkers for achieving efficient and stable all-polymer solar cells

The trade-off between efficiency and stability is a bit vague, and it can be tricky to precisely control the bulk morphology to simultaneously improve device efficiency and stability. Herein, three fused-ring conducted polymer acceptors containing furan, thiophene and selenophene as the electron linkers in their conjugated backbones, namely PY-O, PY-S and PY-Se, were designed and synthesized. The electron linker engineering affects the intermolecular interactions of relative polymer acceptors and their charge transport properties. Furthermore, excellent material compatibility was achieved when PY-Se was blended with polymer donor PBDB-T, resulting in nanoscale domains with favorable phase separation. The optimized PBDB-T : PY-Se blend not only exhibits maximum performance with a power conversion efficiency of 15.48%, which is much higher than those of PBDB-T : PY-O (9.80%) and PBDB-T : PY-S (14.16%) devices, but also shows better storage and operational stabilities, and mechanical robustness. This work demonstrates that precise modification of electron linkers can be a practical way to simultaneously actualize molecular crystallinity and phase miscibility for improving the performance of all-polymer solar cells, showing practical significance. This paper demonstrates that electron linker engineering can be a practical strategy to fine-tune intermolecular interactions and molecular miscibility for simultaneously improving the efficiency and stability of all-polymer solar cells.

Automated summary

This paper demonstrates the importance of electron linker engineering in improving the efficiency and stability of all-polymer solar cells. By designing and synthesizing polymer acceptors with different electron linkers, the intermolecular interactions and charge transport properties of the relative polymer acceptors can be tuned, leading to superior performance and excellent material compatibility.