Fig. 1

Chemical structure and steady state characteristics of F8BT. a Typical chemical structure of F8BT co-polymer system and calculated HOMO and LUMO spatial distribution in F8BT, with isosurface value ± 0.02 a.u. at the TD-B3LYP/6-311 + G(d,p) level of theory. b Absorption spectra of F8BT solution (blue solid line) and solid film (blue dashed line). Photoluminescence (PL) spectra of the F8BT solution in p-xylene (green solid line) and in the solid film (green dashed line). The absorption and PL in solid is red-shifted from the solution