Supersonic seeded beams of thiophene based oligomers for preparing films of controlled quality

A hyperthermal seedable supersonic beam, specifically designed for the deposition of thiophene based oligomers, is presented. The beam's properties are characterized by time-of-flight mass spectrometry and photoionization spectroscopy. Several quaterthiophene (T4) films under different beam conditions have been prepared and characterized by optical absorption, fluorescence spectroscopy and scanning electron microscopy. Centreline heavier species segregation in the beam is exploited to grow T4 films efficiently from impurities present in raw terthiophene (T3) powders. The morphology and structure of the films can be controlled by the beam's parameters that in turn allow variation in flux density, energy and orientation of molecules in the beam.