Figure 3

NR curves (a) and SLD profiles (b) for “PBTTT spin -cast”, “PBTTT slow -dried” and “PBTTT drop -cast” bilayers. Note that the x-axis was normalised to thickness, with a scale from 0 (air interface) to 1 (substrate interface). The total thicknesses of “PBTTT spin-cast” and “PBTTT slow-dried” bilayers are ~120 nm, and ~80 nm for “PBTTT drop-cast” bilayer. All samples were annealed at 185 °C for 10 minutes.