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

A hyperthermal seedable supersonic beam, specifically designed for the depo sition of thiophene based oligomers, is presented. The beam's properties ar e characterized by time-of-flight mass spectrometry and photoionization spe ctroscopy. Several quaterthiophene (T4) films under different beam conditio ns 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 impu rities present in raw terthiophene (T3) powders. The morphology and structu re of the films can be controlled by the beam's parameters that in turn all ow variation in flux density, energy and orientation of molecules in the be am.