A facile approach to alleviate photochemical degradation in high efficiency polymer solar cells

Abstract

In this paper, it is found that residual 1,8-diiodoctane (DIO) which is used as a solvent additive in the manufacture of high-performance polymer solar cells accelerates chemical degradation of the donor polymer PBDTTT-EFT under light and air exposure especially in its blend with PC₇₁BM. Here we report an anti-solvent treatment which can significantly improve device stability while maintaining a device efficiency of ~ 9%. The morphological changes after anti-solvent treatment are also investigated by a combination of synchrotron based techniques.