Polarized micro-Raman measurements of cross sections of single- and multi-layer organic films on glass substrate

Cross sections of single- and multi-layer organic films on glass substrates were investigated with polarized micro-Raman spectroscopy. The apparent band intensity of the cross-sectional measurements of 200 nm-thick monolithic films increased significantly compared to surface measurements because of light propagation inside the organic films. In addition, a drastic difference appeared between the vertical Raman spectra of multi-layer organic films with and without an Al cathode. This can be explained by assuming a slab waveguide and plasmonic wave propagation. The molecular orientation of the single- and multi-layer organic films fabricated by vacuum evaporation is also discussed.