Figure 3. (a) Diagram illustrates the formation of the
PC70BM domain through spinodal demixing. Reproduced from
[89]. (b) The Flory-Huggins theory was used to calculate the phase
diagram of PS:PC70BM:o-xylene. Reproduced from [89]. (c) Aggregate
absorption spectra were recorded for a PCE11 film after spin-coating at
both 70°C and 22°C, with normalization at 1.94 eV. Reproduced from
[94].(d) The morphology-forming process for films made of
polymer:nonfullerene small molecules and polymer:nonfullerene small
molecule:polymer blends is schematically depicted. Reproduced from
[96].(e) Absorption patterns of seq-blade cast films in two
dimensions. Reproduced from [90]. (f) Relative rate of aggregation
for PBDB-T and FOIC. Reproduced from [90]. (g) Corresponding 1D
GIWAXS line profiles. Reproduced from [98]. (h) 2D GIWAXS data of
PM6:Y6 blend films. Reproduced from [98].