Fig. 2

Molecular order of PffBT4T-2DT monolayer. a In-plane GIWAXS line profiles. Profiles are offset for clarity. The in-plane (010) π–π peaks at q = 1.75 Å⁻¹ are indicated by red arrow. A bare substrate (blank) is also measured for reference (The feature at q ≈ 2 Å⁻¹ is parasitic scatter from Si dust). b Schematic illustration of a single nanofiber of PffBT4T-2DT monolayer with an edge-on orientation, in which the brown bricks represent the monomer units of PffBT4T-2DT. The arrangement of backbones relative to each other is idealized. In reality, the monomers might not be in registry