Polarized Pressure Dependence Of The Anisotropic Dielectric Functions Of Highly Oriented Poly(P-Phenylene Vinylene)

In this work, we combined an experimental technique and a detailed data analysis to investigate the influence of an applied pressure on the anisotropic dielectric functions of highly oriented polyp-phenylene vinylene PPV. The dielectric constants were derived from polarized reflectance spectra recorded through a diamond anvil cell up to 50 kbar. The presence of the diamond anvils strongly affects measured spectra requiring the development in an optical model able to take all spurious effects into account. A parametric procedure was then applied to derive the complex dielectric constants for both polarizations as a function of pressure. A detailed analysis of their pressure dependence allows addressing the role of intermolecular interactions and electron-phonon coupling in highly oriented PPV.