Deposition and Solidification of PPV Precursor

Future high performance polymer films will be comprised of molecules oriented in the plane of the substrate. As a first step, a mixture of poly(p-xylene tetrahydrothiophenium chloride) in methanol was spun onto a sapphire substrate. These samples were fabricated over a range of spin-coating times, methanol solution concentrations, and number of drops of solution. Analysis with an ellipsometer revealed that layer thickness is independent of spinning period and applied solution volume, and decreases as the parts per volume of methanol increases. Furthermore, the samples were exposed to various wavelengths of UV-visible radiation to determine the optimal wavelength for driving these precursor molecules into a solid thin film, insoluble in methanol. Light from a mercury arc-lamp with a wavelength of 365 nm was found to solidify the precursor within five minutes of exposure most effectively.