Nonlinear Optical Properties and Organic Gas Effects of VOPc Thick Films Prepared on KBr Substrate

Vanadyl-phthalocyanine (VOPc) thick films were prepared by an organic molecular beam deposition (OMBD) method on KBr substrate. The morphologies and nonlinear optical properties of VOPc films were investigated with VIS/UV spectra, the incident angle dependence of third harmonic (TH) intensity measured by Marker fringe, SEM, and AFM images. The morphology of VOPc thick film prepared at the substrate temperature of 200°C is a pseudoepitaxy. Cracks and wrinkly parts on the film surface are observed from SEM and AFM images. The VOPc thick film exposed for 25 and 50hrs to 1.8 atm organic gas changes from pseudoepitaxy to epitaxy. Cracks and wrinkly parts on the film surface disappear due to the molecular diffusion during the gas treatment. It depends upon time exposed in organic gas. A VOPc thick film treated for 75hrs in 1.8 atm organic gas almost perfectly changes from pseudoepitaxy to epitaxy because it is impregnated with organic gas.