Nonlinear Optical Properties, Vanadyl-phthalocyanine Molecular Orientation and Growing Mechanism on KCl Substrate of Vanadyl-phthalocyanine Thin Film Treated with Thermal Treatment.

Vanadyl-Phthalocyanine (VOPc) thin films are prepared by a molecular beam epitaxy on KCl substrate. The nonlinear optical properties, VOPc molecular orientation and growing mechanism on KCl substrate of VOPc thin film are investigated with UV/VIS spectra, the images observed by SEM and AFM and the second-order harmonic (SH) and third-order harmonic (TH) intensities measured by Maker-fringe. The VOPc thin film treated with a thermal treatment changes from pseudo-epitaxy to epitaxy. Moreover, the surface of the thin film is a plate-like-crystal and smooth. These suggest that the VOPc molecules on KCl substrate are parallel to KCl substrate. The SH and TH intensities of VOPc thin films are increased with thermal treatment. It is closely related to the phase-morpholpgy of VOPc thin film. Therefore, the VOPc thin film epitaxially grown improves the SH and TH intensities.