Fig. 4.

Microstructure of polymer films with and without a molecular additive grazing-incidence X-ray diffraction (GIWAXS) measurements of thick indacenodithiophene-co-benzothiadiazole (IDT-BT) (a, b), diketopyrrolo-pyrrole-dithiophene-thienothiophene (DPP-DTT) (c, d), and poly[[2,5-bis(2-octadecyl)-2,3,5,6-tetrahydro-3,6-diketopyrrolo[3,4-c]pyrrole-1,4-diyl]-alt-(2-octylnonyl)-2,1,3-benzotriazole] (DPP-BTz) (e, f) films on gold substrates; films with the additive (residual 1,2-dichlorobenzene (DCB) solvent) are shown in a, c, e and films with the additive removed are shown in b, d, f