Fig. 5: In situ UV–vis absorption study.

a 2D contour maps, b Positions of 0–1 and 0–0 peaks for donor and acceptor of PM6:NaO1, PM6:NaO2, and PM6:NaO3 blend films.

a 2D contour maps, b Positions of 0–1 and 0–0 peaks for donor and acceptor of PM6:NaO1, PM6:NaO2, and PM6:NaO3 blend films.