Structural characterization of α,ω-DH6T monolayer films grown at the liquid-liquid interface.
Manuel JohnsonTim HawlyMingjian WuErdmann SpieckerRainer H FinkPublished in: Soft matter (2021)
The molecular self-organization of α,ω-dihexylsexithiophene (α,ω-DH6T) monolayers prepared at the solvent-water interface is investigated by complementary microscopy techniques. Our study focuses on the influence of solvents and initial droplet volume on the resulting film morphology. Long-range extended domains in the monolayer regime are detected by visible light microscopy only for toluene. Small-area electron diffraction (SAED) proves the formation of single-crystalline monolayers with structural parameters identical to the organic bulk crystals. In comparison with conventional vacuum sublimated thin films a deviant molecular orientation, derived from near-edge-X-ray absorption fine structure (NEXAFS) in combination with a lower step height measured by atomic-force-microscopy (AFM), indicates a different behaviour of the flexible terminal hexyl chains during growth in a liquid surrounding. Furthermore, a structural degradation over time is observed which is caused by residual solvent molecules that are incorporated during the transfer procedure.
Keyphrases
- atomic force microscopy
- single molecule
- room temperature
- ionic liquid
- high speed
- visible light
- high resolution
- electron microscopy
- high throughput
- solar cells
- air pollution
- body mass index
- minimally invasive
- computed tomography
- crystal structure
- physical activity
- reduced graphene oxide
- electron transfer
- carbon nanotubes